错选E
The meaning should be clear: The costs rose by 2.8% this past year; in the previous year, they rose by more than 2.8%. So, this year, they rose less than they did last year.
"Lower" and "greater" can't be used to compare actions.不能用于动作的比较
lower只能做形容词,不能修饰动词rose;
high/low 不能修饰动作，只能修饰名词。more/less才可以修饰动作，也可以修饰名词。
如果要用lower 需要是 lower than the percentage （they did），而选项中没有percentage或that的指代，可以判断是动作的比较而不是名词的比较。