The mosquito life cycle includes the following stages in order:
1. Egg: Mosquitoes lay eggs on the surface of water.
2. Larva: The eggs hatch into larvae, which live in water and feed on microorganisms.
3. Pupa: Larvae develop into pupae, which are a transitional stage before becoming adults.
4. Adult: Pupae transform into adult mosquitoes, completing the life cycle.
Thus, the correct sequence is (B), (D), (C), (A).