What is the purpose of a "no left turn" sign?

Answer: C — To indicate that left turns are not allowed at that intersection

The purpose of a "no left turn" sign is to communicate to drivers that making a left turn at that particular intersection is prohibited. This restriction is often in place due to safety concerns, traffic flow issues, or the layout of the intersection. By clearly marking the prohibition of left turns, it helps prevent accidents and ensures that traffic moves smoothly in the designated directions. Understanding the significance of such signs is crucial for maintaining safety on the roads and adhering to traffic laws. The other options involve different types of traffic regulations or indicators which do not relate specifically to the left turn prohibition. For instance, speed restrictions would be indicated by a different type of sign, and detour information would be provided to guide drivers around temporary road closures. Likewise, one-way street signs serve a different purpose by indicating the allowed direction of travel on a particular road.