Here's a problem to solve: Clams, oysters, and mussels eat plankton filtered from water. How would clams, oysters, and mussels most likely be affected if the amount of plankton in a large body of water was significantly reduced?

Among the 4 following options, which is the correct answer?

- A: They would increase in number.
 
- B: They would find a new food source.
 
- C: They would become prey to other animals.
 
- D: They would compete for a limited food source.
 