Which of the following statements is correct:
A. In a solution of 1.0 M HCl, [H3O^+] is 1.0 M.
B. In a solution of 1.0 M HF, [H3O^+] is less than 1.0 M.
C. The acid ionization constant of HNO3 is less than that of HNO2.
a) B and C only
b) A and B only
c) A and C only
d) A, B and C