We don’t know that patients get more confused when they’re given more options. Maybe they understand the options, but there is some other reason why being given more options makes them less likely to make changes. It’s important to not make extra assumptions here.

We don’t know that people can’t see a clear difference in benefits between the choices. Like with (A), it’s possible that people can see a clear difference in benefits between the choices, but that there is some other reason why being given more choices results in people being less likely to make a lifestyle change.

(C) says that when given a lot of alternatives, people are less likely to make behavioral changes, and that when given fewer alternatives, people are more likely to make a change. This is the reasoning that the argument relies on, so this is the principle we’re looking for.

The argument says that whether people will follow the doctor’s advice depends on how many options the doctor gives for lifestyle changes. That has nothing to do with being able to imagine the consequences of ignoring the doctor. In fact, regardless of how many options for change the doctor gives, the underlying problem is the same.

Clarity doesn’t necessarily depend on the number of options given — the doctor could be very clear about 10 options or very unclear about 2. Additionally, (E) is making a comparison between the importance of being clear and the importance of a correct diagnosis. The argument doesn’t rely on the relative importance of making a diagnosis and being clear.