The correct option is B Hooks
Rostellum structurally composed of a number of concentric rows of hooks. The two basic types of hooks are those of the upper row, which are larger and had a projecting, rounded stout guard and those of the lower row, which are smaller and have a flattened guard. The main function of the rostellum is attachment. It is protruded during attachment and by the use of hooks penetrates the intestinal mucosa. This is particularly important during digestion of food and bowel movement of the host so that the tapeworm is not expelled along with the feces. So, option C is correct.