In rainy weather, you should be most careful when turning or stopping:

1. After it has been raining all day.
2. One half hour after it stops raining.
3. During the first half hour of rain. ✓

Answer: C. During the first half hour of rain.

You should be most careful during the first half hour of rain.

Why this is the answer

The handbook says that when it starts to rain, the pavement can be very slippery, and you should slow down at the first sign of rain or drizzle. It explains this is especially true if the weather has been dry and hot, since oil and dust on the road have not been washed away yet. So the early minutes of a rainstorm are when the surface is slickest, and that is when turning and stopping need the most care.

Why the other answers are wrong

• A. After it has been raining all day. — After a long day of rain, the oil and dust have already been washed off the pavement, so the handbook points to the start of the rain as the slippery time, not the later hours.
• B. One half hour after it stops raining. — The handbook does not name a half hour after the rain stops as a danger point; it warns about the first sign of rain, when oil and dust are still on the road.

Remember it

Think of the first rain as a wash cycle: the road is slickest while the oil and dust are still being rinsed away.