TOEFL Reading: ETS-TOEFL阅读机经 - XV9M_X6T477FRI3KL$

According to paragraph 4, each of the following is an advantage of using mushroom spores as fertilizer EXCEPT: A. The cost of using mushroom spores is relatively low. B. A single application of mushroom spores is enough for a whole year. C. Mushroom fungi are nutrients that plants can take in easily. D. Mushroom fungi help protect plants from disease.