The correct option is C 10−14
∙ In pure water at 25∘C, the concentration of [H+] and the concentration of [OH−] each are only 1.0×10−7M.
∙ In most cases [H+] and [OH]− are interdependent meaning that when [H+] increase [OH]− decreases and visa versa.
∙ For aqueous solution, the product of hydrogen ion concentration and hydroxide ion concentration equal to 1.0×10−14.
[H]+×[OH]−=1.0×10−14