The correct answer is: (B) Excretion and osmoregulation.
The contractile vacuole in Amoeba plays a crucial role in maintaining the balance of water and waste removal within the cell. This organelle helps in both **excretion** and **osmoregulation**:
Therefore, the contractile vacuole serves as a vital organelle that ensures Amoeba can survive in its aquatic habitat by controlling its internal water content and eliminating waste.