The answer is; A
This is a symbiotic relationship. The mycorrhiza is harbored I the roots of the orchids. The fungi nitrify the soil around the plant. Therefore, the fungi make nitrates (which are critical for the growth of the plant) available to the plant. The fungi, on the other hand, are assisted in breaking down of large carbon polymers by the orchids because the plant’s enzyme is more powerful than those of the fungi.
Based on their cell type, their ability to make food, and the number of cells in their bodies.
24 x 10 to the 8th power. Sorry I don't know how to do the exponents on here