Correct answer: B). With fewer contractions
The main function of a contractile vacuole is to maintain the sufficient amount of water in the protoplasm of the cell. For the freshwater amoeba contractile vacuole is needed to pump water and maintain a osmoregulation.
But when it is kept in sea water, more contraction is required to expel the water out of the cell in order to make the environment inside amoeba same as of sea water.
