A Winter Bud Begins Winter with an Amount of Abscisic

A winter bud begins winter with an amount of abscisic acid to maintain dormancy. Dormancy is broken in the spring because of a(n)

A) gradual reduction in abscisic acid over winter.
B) increase of abscisic acid production by the meristem within the bud.
C) increase in cytokinin in the leaves.
D) gradual reduction of auxin in the shoot tip.
E) gradual increase in ethylene production by the meristem within the bud.