What does a "No U-turn" sign mean?

Answer: D — You may not make a U-turn

A "No U-turn" sign means that you are not allowed to make a U-turn at that particular location. This is usually indicated on roads where it is dangerous to make a sudden turn, such as on a busy road or on a sharp bend. options A, B, and C are incorrect because they suggest that U-turns are allowed in certain situations, whereas the "No U-turn" sign specifically prohibits them. Option B is incorrect because it only specifies U-turns from one one-way street to another, but a "No U-turn" sign applies to all roads. It is important to follow signs and not make U-turns where they are prohibited for the safety of yourself and others on the road.