The correct answer is (A).
(A) Assumption (Sufficient)
Step 1: Identify the Question Type
The question directly asks for something "assumed" by the scientist, making this an Assumption question. The question does also mention that the assumption will "strongly support" the argument, which seems to indicate a Strengthen question. However, while correct answers to many Strengthen questions can simply be information that makes the conclusion more likely, the correct answer here will actually be an assumption that guarantees the conclusion. The approach is the same either way: Identify the conclusion and evidence, and then bridge the gap.
Step 2: Untangle the Stimulus
Before drawing a conclusion, the scientist presents the physicists' assertion. Physicists claim that their peer review process prevents fraud in physics. However, biologists, who made the same claim, ultimately were wrong about the effectiveness of their peer review. Biologists learned from their mistake and enhanced their protections against fraud, which averted further major incidents. The scientist concludes by recommending that physicists make similar enhancements in order to ensure progress in the field of physics.
Step 3: Make a Prediction
In attempting to help physicists, the scientist recounts the biologists' history. The moral of the story: Physicists may want to reassess their precautionary measures if they truly want to be protected from fraud. The scientist does not, however, limit his conclusion to fraud prevention. He claims that taking the recommended steps would be "conducive to progress." It's a classic scope shift. The scientist assumes (perhaps rightly) that scientific fraud impairs the potential for progress in physics.
Step 4: Evaluate the Answer Choices
(A) resolves the scope shift by connecting the idea of scientific fraud (which the evidence addresses) and progress (which the author brings up in the conclusion).
(B) is irrelevant because it only emphasizes the effectiveness of the biologists' new policy in reducing fraud. It does nothing to show how this is conducive to progress; i.e., it does nothing to connect the evidence to the conclusion.
(C) Initially, this choice seems to support the scientist. If no completely effective peer review system exists, then that removes the possibility that the physicists' system is as effective as they claim. However, the scientist doesn't argue for a system that is "completely effective," just that physicists should increase their safeguards. Furthermore, this still doesn't connect fraud prevention to the progress of the field.
(D) is a 180. If the biologists had a worse system 20 years ago than the physicists have now, then perhaps the enhancements the biologists have made since then merely brought them up to the same level as the physicists. In that case, given the biologists' recent success, the physicists would have no need to change.
(E) is also a 180. If physics has been relatively free of fraud, then there seems to be little reason to recommend making any change to the peer review system.
