Oysters are filter feeders. They get their food by moving large amounts of water through their bodies and filtering out whatever is in it. They eat plankton, algae, and similar things that they find in the water. They also remove dirt and chemicals that they find in the water.

How do oysters help other things that live in the water with them?
A.
by removing harmful substances from the water
B.
by removing food from the water
C.
by adding air to the water
D.
all of these