A tells us that the people best at ending their bad habits can vividly imagine the remote benefit. This seems to be supported by the assertion that one of the biggest barriers people face ending bad habits is that they can't do this. Hold this and check the others.
B tells us that the people best at it can imagine their pain in the future. This is not supported, as we're looking for people who imagine benefit in the future.
C tells us they would have modified their behavior in the past, but this isn't addressed in the prompt, so we can skip it.
D tells us that they're unaware of their habits, but we're told at the beginning that most people do know them, and that's why they're trying to change them. It doesn't fit.
E tells us that the people can remember the pain in the past, but the prompt doesn't address the pain of the bad habits, just the pain of stopping them.
