Which of the following mixtures would result in a buffered solution when 1.0 L of each of the two solutions are mixed.
a. 0.4MHNO₃ and 0.8 M NaOH
b. 0.4MHNO₃ and 0.8 M HF
c. 0.4MHNO₃ and 0.4MNaNO₃