Clarification

I was in between C and D, and ultimately went with D because I felt that it was more relevant to the question with stating that motorists who follow the speed limit are in less fatal accidents than those who do not. Although I thought C was the second strongest answer, I ruled it out at the end because the seatbelts and safety measures mentioned are irrelevant to the question stem. If someone could just clarify that my line of thinking is on the right track I’d greatly appreciate it. Thank you