The contractile vacuole of protozoa functions to

Options

A. remove surplus water
B. secrete proteins
C. regulate the pH of the internal milieu
D. digest food materials.

Answer

A

Explanation

A contractile vacuole is found in fresh - water protozoa, it periodically expels water to the outside. In this manner excess water leaves the cell. Due to its osmotic relationship with its environment, water is entering and the cell must maintain the water level of its protoplasm .