When is it permissible to stop in a "No Parking Zone"?

Stopping in a "No Parking Zone" is generally strictly regulated for safety and efficiency reasons, and exceptions are typically limited. The correct answer is the option that highlights clearing the lane for an emergency vehicle. This action is linked to public safety; when an emergency vehicle approaches, it is crucial to ensure that there is an unobstructed route available for it to carry out its duties effectively. By temporarily stopping to create this space, a driver contributes to the urgent need for quick responsiveness in emergency situations, which can be life-saving.

In contrast, other activities such as waiting for a friend, making a phone call, or dropping off a passenger can usually be done elsewhere without obstructing traffic or emergency services. These actions do not prioritize the immediate needs of public safety or the efficient flow of emergency response. Thus, while they may seem reasonable to the driver, they do not align with the primary purpose of maintaining clear passage in a "No Parking Zone."