The Pollen Produced by Wind-Pollinated Plants Is Often Smaller Than

The pollen produced by wind-pollinated plants is often smaller than the pollen produced by animal-pollinated plants. A reason for this might be that

A) wind-pollinated plants, in general, are smaller than animal-pollinated plants.
B) wind-pollinated plants release pollen in the spring, before the plant has stored enough energy to make large pollen grains.
C) small pollen grains can be carried farther by the wind.
D) animal pollinators are more facile at picking up large pollen grains.
E) wind-pollinated flowers don't need large pollen grains because they don't have to attract animal pollinators.