The burning of oil and coal have one negative effect on the environment. what is the negative effect

C) they are specialized meaning they are designed to do different things

The answer is lymph sinuses.

Although i don't know what is the simulated system, starfish are predators that eat mostly  microalgae,  snails, sponges, bivalves, mussels and other small marine animals. removing starfish from any system would definitely increase this animals that they prey.