How would a drought most likely affect the plants of a grassy plain?

Out of the following given choices;

A.      There would be shorter plants

B.      They would have thicker stems

C.      There would be a greater variety

D.      They would have brighter flowers

The answer is  A. Due to lack of water, the plant’s biological processes, including photosynthesis, will be reduced. Due to reduced photosynthesis, the plant will not be able to manufacture enough ‘food’ to support its growth. The root growth will also be stunted and the plant will not have enough reach for the lowering water table. Consequently, the plant will not be able to grow to normal heights.