When can a tow truck be called if towing of a vehicle is not required?

Option B is incorrect because a tow truck can be called even if the vehicle is not completely immobilized. For example, if the vehicle has a flat tire and the driver is unable to change it themselves, a tow truck may be called to tow the vehicle to a nearby mechanic. Option C is incorrect because a tow truck can be called without consulting with a mechanic first. In emergency situations, a tow truck may need to be called immediately without waiting for the advice of a mechanic. Option D is incorrect because a tow truck may also be called if the vehicle is not blocking traffic. For instance, if the vehicle is in a dangerous or hazardous location, a tow truck may be called to safely move the vehicle. Therefore, the best option is A, which states that a tow truck can be called at the request of the driver, even if towing may not be required.