I think the right one is b.
i can think of 3 subatomic particles found in a nucleus protons, neutrons, and electrons
Buffer solutions consist of an aqueous solution of a weak acid and its conjugate base or a weak base and its conjugate acid. Buffer solutions are used to have better control of the pH of solutions.
An example of a weak acid and its conjugate base is acetic acid (CH3COOH) and sodium acetate (CH3COONa).
Cell wall is only plant I believe