Answer:
D. phototropism.
Step-by-step explanation:
Phototropism is the behavior of an organism in which it reacts to sunlight. Tropical trees show an example of phototropism - they need the sunlight and that is why they tend to grow taller and towards the source of light. This is called positive phototropism.
A type of phototropism where plants grow away from the sunlight is called negative phototropism.