you should have a second verb in (e) because the tense changes. in general, if you don't have a second verb, then the implication is that the tense doesn't change.
in standard english usage, "disturbing to X" is usually used only when X is a person whose sensibilities have been disturbed. so this sentence appears to imply that the time period itself was offended.
"have been" implies that those disturbances (or their effects) still continue to this day. that's not true - the sentence implies that the disturbance existed only in that time period - so the present perfect doesn't make sense.
with型独立主格在GMAT中常常被判累赘。with的存在使得some并不是指代colonies,而是与colonies相关的东西;all与后面的a和its单复形式不统一
while必须接完整从句(有谓语动词)或现在分词短语