The following reaction represents a buffer system, which responds to the addition of a base or an acid. Which statement about this reaction is not

The following reaction represents a buffer system, which responds to the addition of a base or an acid.

Which statement about this reaction is not correct?

Select one:

a. The weak acid acts as a proton (H3O+ ) acceptor; the H3O+ ions come from the addition of the strong acid.

b. When a small amount of strong acid is added, Le Châtelier's principle tells you that equilibrium favors the reactant side.

c. Up to a certain point, [H3O+ ] and [OH − ] do not change very much. 

d. When a small amount of strong base is added, Le Châtelier's principle tells you that equilibrium favors the product side.