The calypso orchid, Calypso bulbosa, grows in close association with mycorrhizae fungi. The fungi penetrate the roots of the flower and take advantage of the plant's food resources. The fungi concentrate rare minerals, such as phosphates, in the roots and make them readily accessible to the orchid. This situation is an example of

(A) Parasitism

(B) Commensalism

(C) Mutualism

(D) Endosymbiosis