The cation exchange capacity of clay minerals follows in the order of

Correct option is C

Cation exchange capacity (CEC) is highest in Vermiculite, followed by Montmorillonite, Illite, and Kaolinite. Vermiculite has a high surface area and charge density. Montmorillonite also exhibits swelling properties and good CEC, while Kaolinite has very low CEC due to its 1:1 clay structure.