PTC.S3.Q21- Advertisement for a lactase supplement..

anakin0928

I was stuck between answer choices B and C. I eventually settled down for B but I'm still struggling to figure out why B is the more optimal answer compared to C. The question makes the assumption that the study is representative of the entire population of the United States, and fails to account for any discrepancies between the study subjects and the American population, thus making C an attractive answer.

Clemens_

Lactose (with an O) is a sugar found in dairy. Lactase (with an A) is an enzyme that helps with the digestion of lactose. The author notes that people who take in a lot of lactose (say, one liter of milk) on an EMPTY STOMACH - that is, without also taking in anything else - often have digestion issues. Based on this observation, the author infers that at least 50 million people in the US should take lactase supplements.

There are many gaps in this argument. For example, it is based on a study of people who drink a liter of milk without also taking in anything else (who does that on a regular basis?). (B) picks up on this: According to this answer choice, it is neither the case that most people regularly take in the lactose equivalent of one liter of milk, NOR that they do so on an empty stomach. That is, people typically are not in situations were you could sensibly expect lactose intolerance to be an issue, such that the supplement recommendation does not follow.

(C) seems besides the point. Even if those now affected by lactose intolerance were to cease having this problem as they grow older, there always are new generations of younger people who may or may not be adversely affected. Compared to (C), (B) is a much stronger weakening answer, as (B) indicates that in most cases the alleged problem that the author considers does not even arise.