The Same Bees That Pollinate the Flowers of the Brazil

The same bees that pollinate the flowers of the Brazil nut trees pollinate orchids, which are epiphytes (in other words, plants that grow on other plants) ; however, orchids cannot grow on Brazil nut trees. These observations explain

A) the coevolution of Brazil nut trees and orchids.
B) why Brazil nut trees do not set fruit in monoculture plantations.
C) why male orchid bees do not pollinate Brazil nut tree flowers.
D) why male orchid bees are smaller than female orchid bees.
E) the importance of orchid and Brazil nut tree flowers for the production of orchid bee honey.