The correct answer is B: the different parts of the Earth rotate at different speeds.
This difference in rotational speed causes the Coriolis Effect, which deflects moving air to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. The Earth's rotation means that the equator, which is the widest part of the Earth, moves faster than the regions near the poles. As air moves from high-pressure areas to low-pressure areas, this difference in speed causes the curved paths of air movement.