Answer:
Neither A nor B.
Step-by-step explanation:
If a vehicle is considered to be a rigid body, it does not matter which wheels have the motive force applied. The rigidity of the body transmits the force throughout and moves the vehicle the same, regardless.
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Many factors go into the design of a vehicle and its power train. The amount of force that can bee applied by the tires without spinning is a function of the friction, which is related to the weight on the wheels. Front-engine vehicles tend to have more weight on the front wheels, so driving those wheels makes sense. Other vehicles may have more weight on the rear wheels (due to the weight of a trailer, for example), so rear-wheel drive may make more sense. These choices are sensible because they offer better traction, not because pulling or pushing is "easier"—whatever that means.
If the body is not rigid, it may be easier to pull it than push it. In English, a difficult task is sometimes compared to "pushing a rope uphill." It is difficult because the rope is not a rigid body, so the applied force tends to change its shape, rather than move it in the desired direction.