Tropical Rain Forests Cover About 2% of the Earth's Land

Tropical rain forests cover about 2% of the Earth's land surface, and

A) contain about 2% of the Earth's total biodiversity
B) contain less than 10% of the Earth's total biodiversity
C) contain no more than one-fourth of the Earth's total biodiversity
D) contain up to one-half of the Earth's total biodiversity
E) scientists currently do not know how much of the Earth's total biodiversity is contained in tropical rainforests, although they suspect it is very high