Select the correct option with respect to cockroaches.

In cockroaches, male have paired anal styles on $9^{\text{th }}$ abdominal sternite, which are absent in females. It helps in holding females during copulation. Malpighian tubules are main excretory organs which extract nitrogenous wastes and water from haemolymph and reabsorb certain salts, forming uric acid crystals. Nervous system comprises of a ventral nerve cord and 10 pairs of ganglia. Forewings are highly sclerotised and are not used in flight purpose. They are used to protect the hindwings at rest. Related Theory In cockroach, the wings are two pairs, arises from mesothorax. The first pair of wings are heavily sclerotized and are known as elytra or tegmina. These are protective and cover the hind wings in a folded state, the left tegmen partly overlaps the right. The second pair of wings are membranous and larger, they lie folded below the tegmina when at rest. Each wing has two membranous layers with tubular and chitinous prolongations of the haemocoel between them known as veins or nervures which contain blood in the early stages. Veins are strongly chitinised and enclose $a$ small trachea; the larger veins also contain a fine nerve fibre.