When is it legal to pass on the right?

Answer: B — hen the vehicle ahead is making a left turn

Passing on the right can be dangerous and is often only permissible in certain situations. Option B is correct because it follows the general rule of passing on the right only when the vehicle ahead is making a left turn. In options A, C, and D, the vehicle ahead may not be aware of the driver passing on the right, leading to potential collisions. Additionally, in option C, passing on the right on a single lane road is not legal as it requires crossing over the yellow line. Option D also does not specify what type of road the vehicle ahead is in, so it may not always be legal to pass on the right in that situation. Therefore, option B is the only correct and safest choice.