Why must a driver be particularly careful here?

The vehicle coming from the right has the right of way.
The vehicle coming from the right is not required to signal.
Because there is an increased danger of skidding.
Because a vehicle could come from the left.

Explantion: Where there are fallen leaves on the road surface, your tyres might have reduced grip on the road surface and your braking distances might be greater.

Theory Tester

Why must a driver be particularly careful here?

Managing Risk