The correct option is B Wuchereria bancrofti
Wuchereria bancrofti is a human parasitic roundworm belonging to the phylum Nematoda that is the major cause of lymphatic filariasis. It is one of the three major worms that infect lymphatic system, i.e., lymph glands in humans and block the flow of lymph which leads to the swelling of limbs which appears like limbs of elephant and thus called as elephantiasis.