PrepTest 144, Section 4, Question 7
Dietitian: Eating fish can lower one's cholesterol level.(64 more words not shown)
Which one of the following(27 more words not shown)
- AIt is offered(10 more words not shown)
- BIt expresses the(5 more words not shown)
- CIt rules out(10 more words not shown)
- DIt provides background(7 more words not shown)
- EIt introduces an(10 more words not shown)
Reading the argument
Did the fish make the difference, or were these different groups to begin with?
The two groups ate very similar diets except for the fish. That is a useful comparison. But imagine that one group contained younger people and the other contained older people. Some other difference between the groups might explain their different cholesterol levels.
Then we get an important detail: their average cholesterol levels were similar before the study. That makes the comparison more informative. It doesn't establish that the groups were identical in every respect, but it tells us something about the starting point for the result we're examining.
What we’re looking for
The role question asks what that final detail is doing. The conclusion is the first sentence: eating fish can lower cholesterol. The detail about earlier cholesterol levels provides support for that claim. My broad description would be background about the study that helps support the conclusion; let's find the more precise description in the answers.
Working the answers
- A
This detail helps the dietitian's argument. It doesn't object to the claim that fish can lower cholesterol. Similar starting levels make one possible objection harder to raise.
- B
The conclusion concerns what eating fish can do. The earlier cholesterol levels are information used to support that conclusion, not the claim the dietitian is trying to establish.
- CCorrect
What if the fish-eating group simply had lower cholesterol before the study began? Then its lower average afterward might have nothing to do with eating fish. The final sentence rules out that explanation by telling us the groups started with similar averages. It doesn't eliminate every possible alternative, but it eliminates this particular one.
- D
“Background information” sounds close to our initial description, but finish reading: background on the purpose of the study. This statement doesn't explain why the researchers conducted the study. It gives us a fact about the groups that helps us evaluate the result. Those are different roles.
- E
The sentence removes an alternative explanation rather than introducing one. An alternative would be that some other difference between the groups produced the lower cholesterol. Here we are told that a difference in their starting averages wasn't responsible.
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