Plants respond to which of the following:

The correct answer is: All of the above

The correct answer is d) All of the above.
High temperatures increase the rate of reproductive development and shorten the time during which photosynthesis contributes to fruit and seed production.
Chemotropism is the movement of plants in response to chemical stimuli. Plant sensory responses to external stimuli are based on chemical messengers (hormones). Phytohormones influence all aspects of plants, from flowering to fruit set, maturation, phototropism to leaf defoliation. It is possible that all cells in plants can produce plant hormones.
Phototropism is the ability of plants to move in response to light. For example: sun flowers turn towards the sun.