D) Light , is limited in these rainforest.
Explanation:
Tropical rainforests are characterized by heavy rainfalls and dense forests.
The trees found here are evergreen and form a dense canopy on the forest floor.
Due to this the forest floors of Tropical rain forest do not receive adequate amount of light.
The under shrubs thriving in these region ,need to develop certain mechanism so that they can trap more and more light.
To attain this goal the plants growing on the forest floor of tropical rain forest developed large leaves that have greater surface area to trap more and more light.