Which of the following correctly describes the relationship between hibiscus flowers and bumblebees that eat hibiscus nectar and transfer the pollen of the hibiscus flower?

A. parasitism: bumblebees harm the host hibiscus flowers by removing pollen
B. commensalism: bumblebees live off the nectar but the hibiscus flowers do not benefit
C. predation: bumblebees feed on hibiscus flowers' nectar which causes the hibiscus flowers to die
D. mutualism: bumblebees pollinate hibiscus flowers and hibiscus flowers provide food for bumblebees