The Following Pictures Represent Solutions That Contain a Weak Acid

Multiple Choice

The following pictures represent solutions that contain a weak acid HA (pK_a = 5.0) and its potassium salt KA.Unshaded spheres represent H atoms and shaded spheres represent A^- ions.(K⁺,H₃O⁺,OH^-,and solvent H₂O molecules have been omitted for clarity. )
-Which of these solutions are buffers?

A) (1) and (2)
B) (1) and (3)
C) (1) , (2) and (3)
D) All are buffer solutions.