Final answer:
The speed associated with the absolute minimum gasoline mileage is not necessarily at minimum or maximum speeds, but rather it tends to be poor when the vehicle is not driven at a constant speed. The best fuel efficiency is often achieved at a constant speed within the manufacturer's optimal speed range.
Step-by-step explanation:
The speed associated with the absolute minimum gasoline mileage is typically related to the extremes of operation of a vehicle, such as minimum speed (e.g. idling or stop-and-go traffic) or maximum speed (e.g. high-speed highway driving).
However, neither minimum nor maximum speed consistently correlates with the absolute worst fuel efficiency. Factors such as engine efficiency, aerodynamic drag, and mechanical friction can all influence fuel efficiency.
But by driving at a constant speed, particularly one that is within the optimal speed range recommended by the manufacturer, a driver can generally achieve better gasoline mileage. In the context of the choices provided, the correct answer is d) Constant speed.
It is important to note that when discussing concepts such as average speed and magnitude of average velocity, these are only the same when there is no change in direction, and the car travels at a constant speed.