Haemocoelus vivipary is observed in which insect order is

Answer: Option D

Haemocoelus vivipary is observed in insect order that is Strepsiptera.
Haemocoelus vivipary involves embryos developing free in the female's haemolymph with nutrients taken up by osmosis. This form of internal parasitism occurs only in sterpsiptera and some gall midges.
The Strepsiptera are an order of insects with eleven extant families that include about 600 described species. They are endoparasites in other insects, like wasps, leafhoppers, silverfish, and cockroaches.
Strepsiptera eggs hatch inside the female, and the planidium larvae can move around freely within the female's haemocoel this behavior is unique to these insects. The offspring consume their mother from the inside in a process known as hemocelous viviparity.