A cup of raw milk, after being heated in a microwave oven to 50 degrees Celsius, contains half its initial concentrat...

Virginia on September 1, 2018


Can you please explain why E is the answer. I am able to eliminate the rest of the answers but this one doesn't make sense to me.

2 Replies

Mehran on September 2, 2018

Hi @vreyes95, thanks for your post. Let's start with the stimulus. This one presents an argument: the conclusion is "what destroys the enzyme is not heat but microwaves, which generate heat." This is a cause & effect argument.

The question stem asks you to select the answer choice that weakens the argument. There are three ways to weaken a cause & effect argument. First, you can show an alternative cause. Second, you can show that the cause exists without the effect. Third, you can show that the effect exists without the cause.

Answer choice (E) is correct: it says that what is destroying the enzyme is the *particular kind of heat* that microwaves create in any liquid ("heating any liquid by microwave creates small zones within it that are much hotter than the overall temperature that the liquid will ultimately reach"). So it's an alternative cause: whereas the argument in the stimulus says that "microwaves not heat" are the cause for the destruction of the lysozyme enzyme, (E) says, no, it's the specific way that microwaves heat liquid that causes this effect.

Hope this helps! Please let us know if you have any additional questions.

Virginia on September 4, 2018

Thank you! This really helps.