Vines climb using tendrils. Specialized plant structures respond when they "touch" something like a wall or trellis. The tendrils wrap around the support and the plants are able to climb upwards. This response to touch in plants is called A) germination. B) photosynthesis. C) phototropism. D) thigmotropism.

The answer is d.) thigmotropism

D. Thigmotropism. A "tropism" is a plant movement in response to an environmental stimulus, and "tropo" means "touch." Plant cells change their movements when they detect a change in pressure after having contacted something. It is not A because germination is the sprouting of seedlings. It is not B because photosynthesis is the action of plants to convert light energy into chemical energy. It is not C because phototropism refers to movement in response to a change in light ("photo" means "light").