Answer:
The correct answer would be A. Filter feeders – strain food from water.
Filter feeding is a type of food acquirement in which suspended food material and/or small organisms are strained randomly from the water.
It is accomplished by passing water through the specialized filtering structure.
Examples of filter feeder may include krill, clams, baleen whale, sponges, and many fishes. Few birds like a flamingo and some species of duck also practice filter feeding.
These organisms are considered as ecosystem engineers as they play a crucial role in cleaning water.