Tropical forests contain dense trees, which allow less sunlight to penetrate. emergent

Tropical forests contain dense trees, which allow less sunlight to penetrate. emergent trees are trees that grow to a height of more than 45 to 55 meters, above the usual height of trees in tropical forests. which system provides the best possible explanation for why these trees grow to those heights?
a.
growth pattern
b.
homeostasis
c.
nervous system coordination in plants
d.
phototropism