The correct answer is - B. Increased crash energy.
When speeding, the vehicle apart from gaining more speed, it also gains on much more power, because its weight multiplied by the speed it is moving with is giving it the crash energy, thus the bigger the speed, the bigger the crash energy. When a vehicle crashes, if its speed is very low, than the consequences will be minor, both material, and for the well being of the driver and passengers, but when it is moving much faster than it usually ends up with fatalities because of the much greater crashing energy.