In a plant-pollinator interaction, the plant expends energy to produce colors and scents that attract the pollinator. This energy is therefore not available to use in the plant's growth and reproduction. This interaction provides evidence in favor of which statement?
A) Both partners benefit equally from the relationship. B) Partners join mutualisms for altruistic reasons. C) Conflicts of interest seldom exist in mutualisms. D) Mutualisms may impose costs on the partners.