Q.Pearl oyster belongs to the Class
a. Gastropoda
b. Cephalopoda
c. Scaphapoda
d. Pelecypoda

Pearl culture is the deliberate, commercial production of pearls in oysters, first practised in India at Thoothukudi in 1973, using pearl oysters of the genus Pinctada (marine, ~30 ppt salinity, cultured on racks, rafts or long lines) or the freshwater bivalve Lamellidens; the best pearl beds, on rock ridges and dead coral, yield the finest grade, called 'Lingha Pearl'. A pearl forms naturally when a foreign particle lodges between the mantle and shell, triggering the mantle epithelium to enclose it and continuously deposit concentric layers of nacre — the same mechanism artificial pearl culture exploits at scale by surgically inserting a graft of donor mantle tissue plus a calcareous nucleus into a healthy oyster, then giving it a recovery period before suspending it in cage …