Explanation:
The contractile vacuole in Amoeba plays a crucial role in osmoregulation, which is the process of maintaining water balance. Since Amoeba lives in freshwater, it constantly absorbs water due to osmosis. The contractile vacuole collects excess water from the cytoplasm and expels it out of the cell to prevent it from bursting.

Here’s why the other options are incorrect:

A. To secrete enzyme to digest food particles – The digestive enzymes are secreted by food vacuoles, not the contractile vacuole.

B. To store excess food materials – This function is carried out by food vacuoles, not the contractile vacuole.

C. To excrete nitrogenous waste – Nitrogenous waste is typically excreted through the cell membrane, not by the contractile vacuole.

D. To absorb water from the surrounding – The contractile vacuole does not absorb water; it collects and expels excess water from the cell.