The correct option is B Contractile vacuole - Helps to maintain the shape of the cell
Central vacuole: helps maintain plants' shape and structure by storing water.
Contractile vacuole: pumps water out of protist cells to maintain a suitable concentration.
Food vacuole: storage for molecules that is a food source for the cell
Gas vacuoles: The inflation and deflation of the provide buoyancy, allowing the bacterium to float at a desired depth in the water.