Buffer action 7The diagram shows buffer action by four different buffers on addition of acid or base (x axis).Which of the buffers (a) - (d) in the graph demonstrates the best buffering capacity at pH 5.0pH vs added acid or base in buffer solutionspH 14131211(a)10(d)98(b)765(c)4321012 10 8 6 4 2 0 2 4 6 8 10 12mL acid addedmL base addedSelect one:a. All of these buffers are equally effective as all pass pH 5.0b. Buffer (b)c. Buffer (d)d. Buffer (a)e. Buffer (c)