Being super careful about what the discrepancy is is important to solving this, I daresay. We have two groups of adults - those who work at home and those who don't --- but apparently the dinners that both these groups eat at home are similar in nutritional value, number of courses, and variety of menus EVEN THOUGH one group spends 100 minutes less time per week preparing dinners.
Adults who work outside the home spend, on average, 100 minutes less time each week in preparing dinner than adults who do not work outside the home. But, contrary to expectation, comparison show that the dinners eaten at home by the two groups of adults do not differ significantly with respect to nutritional value, variety of menus, or number of courses.
Which one of the following, if true, most helps to resolve the apparent discrepancy in the information above?
(A) The fat content of the dinners eaten at home by adults who do not work outside the home is 25 percent higher than national guidelines recommend.
Irrelevant. Doesn't address the paradox.
(B) Adults who do not work the home tend to prepare breakfast more often than adults who work outside the home.
Irrelevant. We are talking about dinners here.
(C) Adults who work outside the home spend 2 hours less time per day on all household responsibilities, including dinner preparation, than do adults who do not work outside the home.
We are already told that one group spends 100 minutes less per week preparing dinners. This added info doesn't resolve the discrepancy.
(D) Adults who work outside the home eat dinner at home 20 percent less often than do adults who do not work outside the home.
Yes. If the group that spends 100 minutes less time per week making dinners ALSO eats 20 percent less often at home everything works out. It basically means that the average amount of time per dinner that BOTH groups do prepare dinner is more than likely similar.
(E) Adults who work outside the home are less likely to plan dinner menus well in advance than are adults who do not work outside the home.
Planning in advance or not doesn't resolve the discrepancy. Even if one group ponders over what to prepare for 5 minutes or 1 hour doesn't effectively resolve any discrepancy here, at least not as strong as (D) does.
5 Verbal Tips from a V48 GMAT Tutor