The Evolution of the Horse Shows What Evolutionary Trend(s)

The evolution of the horse shows what evolutionary trend(s) ?

A) The number of structures always increases;therefore complexity always increases.
B) Extinctions are often accompanied by the development of new species.
C) Animals always evolve from gentle grazers toward more vicious omnivores and carnivores.
D) Variations randomly drift from large to small,toward and away from grinding teeth,and to more or fewer toes,proving that evolution is indeed random.