Traveler: Southern Airways has a far worse safety record than Air Dacentaria over the past few years, in terms of both the frequency of accidents and the severity of accidents. Therefore, although Air Dacentaria is slightly more expensive, I will choose it over Southern Airways for my flight from Pederton to Dacenta, since it is worth paying extra to have a safer flight.

Which of the following, if true, casts the most serious doubt on the traveler's argument?

It is illegal to advertise prescription medications in Hedland except directly to physicians, either by mail or in medical journals. A proposed law would allow general advertising of prescription medications. Opponents object that the general population lacks the specialized knowledge to evaluate such advertisements and might ask their physicians for inappropriate medications. But since physicians have the final say as to whether to prescribe a medication for a patient, inappropriate prescriptions would not become more common.

Which of the following would it be most useful to establish in order to evaluate the argument?

When demand for a factory's products is high, more money is spent at the factory for safety precautions and machinery maintenance than when demand is low. Thus the average number of on-the-job accidents per employee each month should be lower during periods when demand is high than when demand is low and less money is available for safety precautions and machinery maintenance.

Which of the following, if true about a factory when demand for its products is high, casts the most serious doubt on the conclusion drawn above?

Over the last five years, demand for hotel rooms in Cenopolis has increased significantly, as has the average price Cenopolis hotels charge for rooms. These trends are projected to continue for the next several years. In response to this economic forecast, Centennial Commercial, a real estate developer, is considering a plan to convert several unoccupied office buildings it owns in Cenopolis into hotels in order to maximize its revenues from these properties.

Which of the following would it be most useful for Centennial Commercial to know in evaluating the plan it is considering?

Paleontologist: About 2.8 million years ago, many species that lived near the ocean floor suffered substantial population declines. These declines coincided with the onset of an ice age. The notion that cold killed those bottom-dwelling creatures outright is misguided, however; temperatures near the ocean floor would have changed very little. Nevertheless, the cold probably did cause the population declines, though indirectly. Many bottom-dwellers depended for food on plankton, small organisms that lived close to the surface and sank to the bottom when they died. Most probably, the plankton suffered a severe population decline as a result of sharply lower temperatures at the surface, depriving many bottom-dwellers of food.

In the paleontologist's reasoning, the two portions in boldface play which of the following roles?

The symptoms that United States President Zachary Taylor began showing five days before his death are consistent with arsenic poisoning. Recent examination of Taylor's bones, however, revealed levels of arsenic comparable to those found in the bones of Taylor's contemporaries. These levels are much lower than the levels of arsenic that remain in the bones of arsenic poisoning victims who live for more than a day after ingesting a lethal dose of the poison.

Which of the following is most strongly supported by the statements given?

An advertising agency must leave its office building. To save overhead costs, it is considering setting up a "virtual office" instead of moving to an adjacent office building. Employees will do their work on computers, as they do now, but will do so at home, sharing their work with colleagues by communicating text and designs to colleagues' computers through telephone lines, receiving typed comments, and then revising the work until it is satisfactory.

Which of the following, if true, indicates a disadvantage of the virtual office plan?

To prevent harbor porpoises from getting tangled in its nets and suffocating, a fishing company installed acoustic alarms on all its boats that fish in waters off Massachusetts. The sound emitted temporarily disorients the porpoises and frightens them away. Since the installation of the alarms, the average number of porpoises caught in the company's nets has dropped from eight to one per month. The alarms, therefore, are saving the lives of harbor porpoises in those waters.

Which of the following is an assumption on which the argument depends?

Hutonian Government Official: Federal law requires truck drivers to take a long break after driving for ten hours, but truck drivers frequently do not comply. Since the public rest areas along our highways cannot accommodate all the drivers needing a break, we plan to build more rest areas to increase the rate of compliance.

Hutonian Business Representative: But if the parking lots around our businesses are considered, there are more than enough parking places.

Which of the following, if true about Hutonia, would provide a reason for persisting with the government official's plan despite the objection?

Among people who experience migraine headaches, some experience what doctors call "common" migraines, whereas others experience "classical" migraines. Siblings and spouses of common migraine sufferers are themselves twice as likely as the general population to experience common migraines. Siblings of classical migraine sufferers are four times more likely than the general population to experience classical migraines, whereas spouses of classical migraine sufferers are no more likely than the general population to experience such headaches.

The information above provides the most support for which of the following hypotheses?