Lady bird beetle function as a biological controlling agent against Aphids. Glomus is a genus of arbuscular mycorrhizal fungi and it form symbiotic relationship with plant roots which is called mycorrhiza. Tricoderma is used as a biological controlling agent against pathogenic fungi belonging to various genera. Methanobacterium produce methane which is the main component of Biogas.So, the correct option is '(I)-C, (ii)-D, (iii)-B, (iv)-A'