How many minutes after it has rained are the roads most dangerous due to the mixing of rain with oil and debris?

The correct choice emphasizes that the roads are most dangerous during the 10-15 minutes after it starts to rain. This period is critical because the initial rainfall mixes with the accumulated oil and debris on the road surface, creating a slippery and hazardous condition. These oils are often laid down from vehicles over time, and when rain first begins, it interacts with these substances to form a slick, viscous layer.

As the rain continues, the oil is gradually washed away, making the road surface less hazardous. This is why the most dangerous time is right at the beginning, before thorough rain has fully washed away the oil and debris. Understanding this timing can help drivers remain vigilant and adjust their driving behavior during those first few minutes of rainfall.