A new Johns Hopkins study that analyzed cancer incidence by birth year

VERITAS PREP OFFICIAL SOLUTION:

As you assess your decision points in this problem, you should recognize that the most glaring difference between answer choices is in the verbs at the end of each choice - some are singular, some are plural, and the tenses vary, as well. This should force you to look back for clues that suggest singular vs. plural and the timeline of the sentence.

In choice A, the subject of that verb "are increasing" is "the rate of colorectal cancer." The subject is singular but the verb is plural, so choice A is incorrect.

Choice B is more about verb tense, and the order is out of place. The earlier-in-time group (people born between 1890 and 1950) get the ongoing verb "have dropped" but the more recent group gets the simple past "increased," and that's paired with the just-past-the-underline signal "since" which typically suggests that the event is ongoing. This creates an illogical sequence of events, rendering choice B incorrect.

Choice C goes back to a simple subject-verb misalignment, with the plural subject "rates" and the singular verb "is increasing." Therefore choice C is incorrect.

Choice E commits another tense error. By saying that "rates increase" the sentence is suggesting that increasing is what those rates always do, and not that they have been increasing (a trend). Therefore choice E is incorrect.

Choice D, which properly pairs the plural "rates" with the plural "have been increasing," and creates a logical timeline with its verb tenses, is correct.

An important note: when you determine that you are likely dealing with a tense/timeline issue, you should be sure to look outside the underlined portion for clues that signal the proper timeline. Words like "after," "before," "during," or here "since" are easy for the testmaker to hide far from the underline where students often overlook the critical importance those words hold with regard to tense. Here "since 1950" calls for an ongoing timeline for the verb "increasing," a crucial point that can be easy for students to miss.