Which line marking indicates that passing is allowed when safe?

Answer: A — A broken yellow line

A broken yellow line indicates that passing is allowed when it is safe to do so. This type of marking is used to separate lanes of traffic moving in opposite directions, and its presence signifies that drivers may cross over the line to overtake another vehicle, provided they have a clear view of oncoming traffic and it is safe to make the maneuver. The broken nature of the line allows for this flexibility, as it suggests that although passing is generally permitted, caution must be exercised. In contrast, a double yellow line indicates that passing is not permitted under any circumstances, while a single yellow line typically suggests that passing is discouraged and may only be permitted at certain times or in specific situations. A solid red line often conveys an entirely different message related to stopping or parking restrictions, further reinforcing that it does not pertain to passing. Understanding these markings is crucial for safely navigating roads and ensuring compliance with traffic laws.