The correct option is B Mulberry leaves
Sericulture is the production of raw silk by means of raising caterpillars (larvae), particularly those of the domesticated silkworm (Bombyx mori). Silkworm larvae are fed with mulberry leaves, and, after the fourth moult, climb a twig placed near them and spin their silken cocoons. This process is achieved by the worm through a dense fluid secreted from its structural glands, resulting in the fibre of the cocoon. Hence, option C is correct.