Which of the following statements concerning the flow of traffic is accurate?

a. it’s safer to drive slower than other vehicles on the road.
b. driving slower or faster than vehicles around you tends to disrupt the flow of traffic.
c. you can decrease the chances of a collision by driving faster than surrounding traffic.
d. both b and c are correct

I would say B. Driving slower or faster than vehicles around you tends to disrupt the flow of traffic. 

The correct answer is B. Driving slower or faster than vehicles around you tends to disrupt the flow of traffic. This is because driving slower, especially on 2-lane roads, can cause major traffic backup and put everyone in more danger. Driving slower around other vehicles isn't safe for the same reason, and driving faster is also not safe because you put yourself at a higher risk for a car accident. The safest way to drive is the speed of the vehicles around you up to the speed limit.