Filaria, a parasitic disease caused by the filarial worms, is transmitted through the bites of certain types of mosquitoes. The correct answer to this question is option 3: Culex mosquito. Culex mosquitoes are the vectors responsible for transmitting filarial worms to humans. These mosquitoes become carriers of the infection when they ingest the microfilariae (larval stage) of the worms while feeding on an infected person`s blood. Once inside the mosquito, the microfilariae develop into infective larvae. When the infected mosquito bites another person, it transmits the infective larvae into their bloodstream, thus causing the transmission of filaria. It is important to note that other mosquitoes, such as Aedes and Anopheles, are not the primary vectors for filaria transmission.