The diagram shows that the upwind side of a mountain range tends to receive more precipitation than the downwind side of a mountain range. The prevailing winds are shown as an arrow that moves across the ocean, up the side of a mountain range, and down the other side of the mountain range. The upwind side of the mountain has vegetation and rain clouds. The downside is drier. Which statement is MOST USEFUL for explaining this observation? A. Prevailing winds flow from west to east. B. Water vapor condenses to form droplets of liquid water. C. Evaporation allows water vapor to rise through the air. D. Cold air holds less moisture than warm air.