Question

In autumn, many trees shed their leaves and change their color. Which explains the reason for this behavior?
In autumn, the amount of ethylene decreases, rendering the cells of the abscission layer more sensitive to auxin.
In autumn, the amount of auxin decreases, rendering the cells of the abscission layer more sensitive to ethylene.
In autumn, the amount of gibberellins decreases, rendering the cells of the abscission layer more sensitive to auxin.

Answer 1

@theDeviliscoming

Answer 2

In autumn, the amount of ethylene decreases, rendering the cells of the abscission layer more sensitive to auxin.