Many Species of Trees Found in the Canopy and Emergent

Many species of trees found in the canopy and emergent layer of forests have seeds and saplings that are shade adapted.Why do you think this is?

A) The seeds need a low temperature to germinate and grow.
B) The seeds and saplings will be in the shade for much of their early life because the parent trees in the upper layers of the forest will block a portion of sunlight.
C) There is a higher level of humidity in the shade,which the saplings need to survive.
D) In order for animals to find and eat the seeds,a necessary step in the trees' germination cycle,they must be on the forest floor.
E) Canopy and emergent-layer trees do not produce shade-adapted saplings.