Research Has Shown That Cytokinin Levels Fluctuate Seasonally in Temperate

Research has shown that cytokinin levels fluctuate seasonally in temperate plants. What season would you expect to see the lowest levels of cytokinins and why would this be adaptive?

A) Spring, because lower levels of cytokinin allow auxin to promote rapid growth the height for stems. This will allow the plant to compete effectively for sunlight.
B) Summer, because lower levels of cytokinin would slow growth down and delay leaf aging. This will allow the plant to maximize the production of starch and increase it's sugar reserves. This will help ensure the plant's survival through Autumn and Winter.
C) Autumn, because lower levels of cytokinin at this time of year will induce the production of ethylene. This will result in maturation of fruit and ensure effective seed dispersal before Winter.
D) Winter, because lower levels of cytokinin will place buds into a dormant state. This will protect the underlying tissues from freezing until Spring.