Refer to the Figure Below, Showing Two Plants of the Same

Refer to the figure below, showing two plants of the same type grown under different experimental conditions. Which scenario describing the use of mutant plants in hormone studies such as this one is realistic?

A) The plants are both normal, but only one has been subjected to a genetic screen.
B) The plants are both dwarf mutants, but only one has been subjected to a genetic screen.
C) The plants are both dwarf mutants, but one has grown to normal proportions after being treated with an external application of a growth hormone such as gibberellin.
D) The plants are both normal, but one reversed its growth and became a dwarf after being treated with a growth hormone inhibitor.
E) The plants were subjected to different regimes of red and far-red light.