When Auxin Accumulates on the Lower Side of the Root

When auxin accumulates on the lower side of the root of a germinating seed, it:

A) decreases cell elongation on the lower side of the root.
B) increases cell elongation on the lower side of the root
C) decreases the use of energy by the cells in the root.
D) increases the use of energy by the cells in the root.
E) has no effect on the root (it affects only the developing shoot) .