Question:

Rain, snow, and ice impair your ability to see ahead, so you must _________ to be able to stop your vehicle safely.

A increase your following distance.

Explaination

Bad weather calls for slower speeds. You should follow other vehicles at a greater distance. Rain, snow, and ice impair your ability to see ahead and increase the braking distance required to stop your vehicle. In these conditions, increase your following distance and apply your brakes sooner but more gently than usual. [Driving in Rain or Snow; Special Driving Situations; California Driver Handbook]