Calculate either [H3O+] or [OH−] for each of the solutions at 25 °C.
Solution A: [OH−]=3.31×10−7 M; [H3O+]=
M
Solution B: [H3O+]=8.17×10−9 M; [OH−]=
M
Solution C: [H3O+]=5.91×10−4 M; [OH−]=

Which of these solutions are basic at 25 °C?