In which circumstance is it legal to pass another vehicle on the right?

Answer: A — When the vehicle ahead is turning left on an all-way street with more than two lanes

Passing another vehicle on the right is legal when the vehicle ahead is turning left on an all-way street with more than two lanes. This situation creates an opportunity for vehicles to continue moving straight or to the right without needing to wait for the left-turning vehicle to complete its maneuver. In many cases, multi-lane roads allow this safe form of passing as long as it can be done without endangering other drivers or pedestrians. In contrast, passing on the right in a construction zone or when traveling below the speed limit could lead to dangerous situations, as construction zones often have altered traffic patterns, and traveling below the speed limit does not equate to a safe opportunity for passing. Similarly, when the vehicle ahead is parked, it is generally safer to stay behind it or change lanes instead of attempting to pass it on the right, as this could lead to unexpected obstacles or hazards. Thus, the scenario of having a vehicle turn left on a multi-lane road is the clear instance where passing on the right is permitted.