What does a blue sign with an arrow pointing left indicate?

Answer: C — One-way road.

A blue sign with an arrow pointing left is an indication of a one-way road where vehicles are permitted to travel only in the direction of the arrow. This means that drivers must follow the direction specified by the arrow and cannot turn or navigate against it. Such signs are critical for maintaining traffic flow and safety, as they help prevent confusion about which direction is legal for vehicles to travel on a given road. The indication of one-way traffic is important for both drivers and pedestrians because it helps establish clear expectations and guidelines for movement in that area. This centralized understanding of road rules contributes to overall road safety by minimizing the risk of accidents caused by vehicles traveling in the wrong direction.