What external changes are visible after the last moult of a cockroach nymph?
A) Mandibles becomes harder
B) Anal cerci develop
C) Both forewings and hind wings develop
D) Labium develops

Hint:In cockroach, development is pauro metabolous. It develops by shedding about multiple times to arrive at the grown-up structure.

Complete answer:
The closest to the last nymphal stage has wings. And-centric cerci are a couple of jointed filamentous structures in tenth portion of both genders. The labium is a lower lip and a couple of mandibles are available in mouthparts of a cockroach. In cockroaches, improvement is pauro metabolous. The nymph develops by shedding about 13 times to arrive at the grown-up structure. The closest to the last nymphal stage has wings. And-centric cerci are a couple of jointed filamentous structures in the tenth segment of both genders. The labium is a bottom lip and a couple of mandibles are available in mouthparts of a cockroach.

Hence, the correct answer is option (C) Both forewings and hind wings develop.

Note: Nymph of cockroach rise out from ootheca. It resembles grown-up as a rule structure however comes up short on the wings and develops contraceptive organs. Instar an enormous stage in the advancement of bugs (larval instar, nymphal instar). Period between two sheds in bugs is named arena. In periplaneta Yankee folklore the sprite develops by shedding around multiple times to arrive at the grown-up from blatta orientalis sheds multiple times.Metamorphosis is managed by two hormones, ecdysone discharged by prothoracic organs and adolescent hormone emitted by corpora allata.