In insects the 1st pair of post oral appendages are

Answer: Option C

In insects the 1^st pair of post-oral appendages are Maxillae.
Pair of structures called first maxillae, each consisting of a bladelike lacinia, a hoodlike galea, and a segmented palp bearing sense organ.
The paired second maxillae are partly fused in the midline to form the lower lip or labium.