PT 65, S4, Q10 (Explain a Result)
(D) is correct.
With an Explain a Result question, you shouldn’t go looking for any kind of conclusion or supporting premise. Instead, simply look at the information and try to identify what the expected result would have been. From there, see if you can figure out what led to the unexpected result.
In this case, we have people decreasing their consumption of red meat by one-half in order to reduce the amount of fat in their diets. What would be the expected result? Well, meat obviously has a lot of fat in it, so reducing the amount of meat you eat should lead to a lower fat intake. But we’re told that the people who reduced their consumption of red meat actually consume more fat than those who did not.
What might cause this discrepancy? Obviously, eating less fat has to lower someone’s fat intake. The only way the people in question could end up eating more fat is if they get that fat in some other way.
(A) This passage is talking about the average change in the fat intake of two populations (those who reduced their consumption of red meat and those who didn’t). The actual number of people in each of these categories is irrelevant.
(B) Price is entirely out of scope here.
(C) This answer choice is very tricky. At first glance, it seems to give us what we wanted: the people who reduced their consumption of red meat have been getting the fat somewhere else! Case closed, right? Unfortunately, it only says that they eat the same amount of other high-fat foods as the people who didn’t reduce their consumption of red meat. So we would still expect those people who cut down on their consumption of red meat to be consuming less fat than those who did not.
(D) Here we go. If the red-meat-cutter-outters replaced the fatty meat with foods that are "richer in fat than red meat," we would expect their fat intake to be higher than that of those who did not cut out red meat.
(E) This still wouldn’t explain how people who cut out red meat would end up eating more fat than those who kept on eating the same amount.