Fish which can be used in biological control of mosquitoes/larvicidal fish is (a) Eel (b) carp (c) cat fish (d) Gambusia.
Option D Gambusia is a species of freshwater fish. It is remarkably hardy, surviving in waters of very low oxygen saturations, high salinities and high temperatures. For these reasons, this species may now be the most widespread freshwater fish in the world, having being introduced as a biocontrol in certain countries to control mosquitoes. It feeds on larval and pupal stages of mosquitoes