Correct Answer: Cation -A
Given that both the cations, cation-A and cation -B have the same concentrations.
Charge on cation-A is +3, while charge on cation- B is +1. Cations with higher charge can easily substitute those present on the clay minerals. Cations with higher charge have a greater affinity for the negatively charged sites present on the clay mineral. So, cation -A with a charge of +3 is more likely to occupy the anionic sites on the clay mineral.