The values of \({K_{\text{w}}}\), the ionic product constant of water, are:

Which statements are correct?

I.     The \({\text{[O}}{{\text{H}}^ - }{\text{]}}\) in water is less than the \({\text{[}}{{\text{H}}^ + }{\text{]}}\) at 18 °C.

II.     The ionization of water is an endothermic process.

III.     The pH of water is lower at 25 °C than at 18 °C.

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

C