One Experiment in Phototropism Involved Cutting Off the Tips of Grass

Multiple Choice

One experiment in phototropism involved cutting off the tips of grass seedlings before exposing them to light from one side. The decapitated seedlings did not bend toward the light. A valid conclusion from this experiment would be that

A) plants cannot engage in photosynthesis without the tip of the plant.
B) light is perceived by the tip of grass plants.
C) a foil cover over the tip of the seedlings would cause them to bend.
D) hormones are produced in all parts of the plant.