Your ability to stop is affected by:
- Signal lights.
- Other cars on the road.
- The time of day.
- The condition of the road. ✓
Answer: D. The condition of the road.
Your ability to stop is affected by the condition of the road.
Why this is the answer
The handbook says to set your speed and following distance according to the condition of the vehicle and the road, and it singles out wet roads: they become slippery, so the car is harder to control. It also says you must be able to stop within the distance you can see. A slippery or poor road surface changes how much grip your tires have, so it changes your stopping ability. That is why road condition is the listed factor.
Why the other answers are wrong
- A. Signal lights. — Signal lights tell other drivers what you plan to do; the passage does not say they change how quickly your vehicle can stop.
- B. Other cars on the road. — Other cars are a reason to adjust following distance, but they do not describe the road surface or grip that determines stopping ability.
- C. The time of day. — The time of day is not the factor the handbook names; it mentions limited vision in the dark, but that is about seeing distance, not the condition that changes stopping grip.
Remember it
Think grip, not clock: ask what the road surface is like before you decide how fast you can stop.