In which insect, Ovipositor is modified into spine

Answer: Option C

In Wasp insects, Ovipositor is modified into spine.
The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages.
In the wasp genus Megarhyssa, the females have a slender ovipositor several inches long like spine that is used to drill into the wood of tree trunks. These species are parasitic in the larval stage on the larvae of horntail wasps, hence the egg must be deposited directly into the host's body as it is feeding. The ovipositors of Megarhyssa are among the longest egg-laying organs.