The correct option is D Four pairs of legs
Insects belongs to phylum arthropod. They have a segmented body, each segment bearing a pair of jointed appendages.
Chitinous exoskeleton is secreted by the underlying epidermis. The body is divided into head, thorax and abdomen. In some cases, the head and thorax is fused to form cephalothorax.
In insects, the thoracic segments have legs and wings, the abdomen has no legs in insects. So, arthropod phylum have a chitinous exoskeleton, a three-part body (head, abdomen and thorax) and three pairs of jointed legs (total 6 legs), compound eyes and one antennae.
Therefore, option d is incorrect.