Bunuel
Over the past two years, legislators have been revising environmental regulations and creating new restrictions that are increasingly difficult for companies to circumvent them.
A. legislators have been revising environmental regulations and creating new restrictions that are increasingly difficult for companies to circumvent them
B. legislators have revised environmental regulations and created new restrictions that are increasingly difficult for companies circumventing them
C. legislators are revising environmental regulations and creating new restrictions that are increasingly difficult for companies to circumvent
D. while legislators have been revising environmental regulations and creating new restrictions, it is increasingly difficult for companies to circumvent them
E. legislators have revised environmental regulations and created new restrictions that are increasingly difficult for companies to circumvent
VERITAS PREP OFFICIAL EXPLANATION
This problem provides two major decision points: the tense of the verb "revise," and the presence or absence of the pronoun "them."
You should note that the only portion of the sentence not underlined is a signal of timeline "over the past two years." This is an ongoing event that started in the past, suggesting that you'll need the "have revised" or "have been revising" tense. Choices B and C do not provide tenses that will work with the timeline, and can be eliminated.
From there you need to look at the pronoun "them." This pronoun is unnecessary, as you would never say "created new restrictions that are difficult for companies to circumvent the restrictions." Since only choice E avoids the pronoun and provides a logical verb tense, choice E is correct.