Sharks are the top predator in a marine ecosystem. By eating them, sharks maintain a balance in the population of smaller organisms. If the shark's population were to decrease, the smaller organisms would increase greatly, interrupting the food web. Which of the following relationships is MOST similar to the relationship between the shark and the marine ecosystem?
A. A frog eats flies and lizards in a swamp ecosystem.
B. Leaf-cutter ants eat grass in a prairie ecosystem.
C. A wolf eats small mammals in a forest ecosystem.
D. An owl eats mice and insects in a forest ecosystem.