Hi Sachin,

The CR question uses a bit of "representativeness"-logic (meaning a small sample is used as a way to assess a larger group).

The Facts:
-The introduction of a new drug into the market should be contingent upon (based on) our having a GOOD UNDERSTANDING of its SOCIAL IMPACT.
-The SOCIAL IMPACT of the newly marketed ANTIHISTAMINE is FAR FROM CLEAR.

Conclusion:
-There should be a general REDUCTION in pace of bringing NEW DRUGS that are being tested to market.

The Logic:
-The Advocate argues that having a GOOD UNDERSTANDING of a drug's SOCIAL IMPACT is important BEFORE introducing a new drug to the marketplace. Since the social impact of a new ANTIHISTAMINE is unclear, there should be a REDUCTION in pace of bring any NEW DRUGS BEING TESTED to market. This argument assumes that the issue with this new antihistamine (not knowing the social impact) is representative of all new drugs being tested. So if we slow down the introduction of this antihistamine, we should slow down the introduction of new drugs being tested.

We're asked to STRENGTHEN the logic, so we need an answer that confirms that the new drugs being tested are similarly not understand (as the new antihistamine). Answer A goes a step further by telling us that the new antihistamine is MORE understood than the new drugs being tested. Since the understanding about the antihistamine is unclear, the new drugs are even MORE unclear.

Answer B is almost what we're looking for, but this answer doesn't logically link the new drugs to the other evidence in the prompt. It also states that SOME of the new drugs are poorly understood, but we're not sure how many drugs that is (it could be just a few or it could be many) - this doesn't match the far-reaching conclusion presented in the prompt.

GMAT assassins aren't born, they're made,
Rich