The response of a plant to touch is
a. photoperiodism.
b. phototropism.
c. gravitropism.
d. thigmotropism.

D. thigmotropism refers to the response of a plant to contact or touch. It often dictates how plants grow in in a particular pattern, such as the vines growing in fences. The plant Mimosa or tickle me plant does not display thigmotropism but thigmonasty because it does not follow the direction of the stimulus.

The correct answer is c