Final answer:
At 25 mph on a clear city road, a motorist should be able to see about one block ahead, which is essential for safe driving. The correct option is a.
Step-by-step explanation:
When driving at 25 mph on a clear road in a city, a motorist should be able to see about one block ahead. This visibility helps maintain safe driving practices and allows adequate time for the driver to respond to any unforeseen circumstances or hazards that might occur.
It's important for drivers to adjust their driving speed and following distance to ensure clear visibility, as conditions such as weather, traffic, and road design can influence how far ahead one can see. The correct option is a.