For the titration of 25.0 mL of 0.100 M C₅H₅N(aq), pyridine, with 0.100 M HC(aq), the main species in solution after the addition of 12.5 mL of acid are:
a. C₅H₅N(aq), C₅H₅NH⁺(aq) and CI⁻(aq).
b. C₅H₅NH⁺(aq), and CI⁻(aq).
c. C₅H₅N(aq), OH⁻(aq), and CI⁻(aq).
d. C₅H₅N(aq).