Final answer:
A change in the concentration of products does c) not affect the value of Ka; it remains constant as the reaction adjusts to maintain the established equilibrium.
Step-by-step explanation:
The higher the concentration of products, the c) no effect on Ka because the value of Ka (acid dissociation constant) does not change with changes in concentration of reactants or products. Ka is a specific value at a given temperature that characterizes the dissociation of a weak acid in water. If only the concentrations of reactants or products are changing, the system will simply shift to re-establish equilibrium, but the ratio defining Ka and therefore its value will remain constant according to Le Châtelier's principle.