The reason why E doesn't help is because E requires us to go one more step to explain why people aren't wearing seat belts?(because they are not obeying the law?)
http://7sage.com/lsat_explanations/lsat-37-section-2-question-17/
... .com/lsat_explanations/lsat-56-section-3-question-20/
The argument ... (D) without hesitation. The question stem asks "which one of ... heart disease. Furthermore, the question stem asks for "most weaken ... to (B) given the question stem?