Question

1. in the tropical rainforest plants must compete for

a. air.
b. water.
c. heat.
d. sunlight.

Explanation:

In tropical rainforests, there is abundant rainfall (so water is not a major limiting factor), the air is generally present (not a key limiting resource for competition in the context of plant growth compared to another factor), and heat is also in sufficient supply. However, due to the dense canopy of tall trees, sunlight is a scarce resource that plants (especially under - story plants) need to compete for to carry out photosynthesis.

Answer:

D. sunlight