Prior to sowing of crop seeds, these plants are grown and then mulched by ploughing them into the soil. Which of the following statements is not correct about them?
(A) These plants turn into a kind of manure called vermicompost
(B) These include sunnhemp, guar, Berseem etc
(C) These plants help in enriching the soil in nitrogen and potassium
(D) Both (A) & (C).
correct answer is ( a )