Answer: C. The orchids receive water and oxygen from the fungi, while the fungi receive food and minerals from the orchids.
Mycorrhizal association refers to the mutualistic symbiotic relationship between a fungi and roots of vascular plants. In this type association both partners are benefited.
The plant roots are unable to take nutrients which are chemically or physically immobilized in the soil. The mycelium of the mycorrhizal fungus helps to avail those nutrients to the plants. Thus plants are able to obtain phosphates and iron through these fungi. These fungi also, increase the water absorption capacity of plants. In return the fungi receives the direct access of carbohydrates like glucose and sucrose. These carbohydrates translocate from leaves to roots, from there fungi receives these carbohydrates as food source.
The plant orchid and fungi of phyllum basidiomycota form mycorrhizal association, which is a mutalistic association. Thus, the orchids receive water and oxygen from the fungi, while the fungi receive food and minerals from the orchids.