Which of the following statements best explains the absence or sparcity of undergrowth in the equatorial rain forest?

• A.Very little rain reaches the ground because of the dense vegetation
• B.There is too much precipitation which destroys the undergrowth
• C.the taller trees cut off most of the sunlight
• D.most of the precipitation is usually cleared by run-off after heavy thunderstorms
• E.the trees have very strong and large roots which prevent undergrowth