When is passing another vehicle prohibited?

Answer: B — When the traffic situation is unclear

Passing another vehicle is prohibited when the traffic situation is unclear because it can be dangerous and may lead to accidents. In unclear situations, a driver may not have a complete view of the road ahead, which increases the risk of encountering oncoming traffic, obstacles, or other hazards. Making an attempt to pass in such circumstances could endanger not only the driver but also other road users. It's essential for drivers to ensure they have clear visibility and sufficient space before attempting to pass another vehicle. This includes understanding the dynamics of the road and being aware of any potential risks that may arise during the maneuver. Clear traffic situations allow for safer decisions and proper execution of passing, while unclear situations inherently increase the chance of an accident.