A Friend Complains That All of Her Houseplants Have Bent

A friend complains that all of her houseplants have bent stems. You examine the plants and find that their stems all curve toward the light. What would you recommend to your friend to correct the problem?

A) Turn each plant occasionally so that different sides will face the light.
B) Apply an auxin to the shady side of the stems.
C) Water the plants more frequently.
D) Apply gibberellins to the bases of the stems.
E) Repot the plants.