The correct option is B Minimise rate of transpiration
Certain plants which have Crassulacean Acid Metabolism (CAM) are known as CAM plants. They have scotoactive stomata. Their stomata remain open during the night. This is done because they tend to minimise the rate of transpiration. It is the characteristic feature of CAM plants. These plants fix carbon dioxide during the night but form sugars only during the day when RuBisCO is active. Sedum, Kalanchoe, Pineapple, Opuntia are the examples of CAM plants. These plants also perform double carbon dioxide fixation. The carbon dioxide acceptor in CAM plants is Phosphoenol pyruvic acid (PEP) during the night and Ribulose bisphosphate is carbon dioxide acceptor during the daytime. The first stable product in case of CAM plants is Oxalo acetic acid (OAA).