Number of water of crystallization in potash alum are:

Identify the formula of a monobasic acid having $3 {\mathrm{OH}}^{-}$ groups present and having IUPAC name Boric acid.

$$\begin{gathered} \mathrm{A}: {\mathrm{H}}_2{\mathrm{BO}}_3 \\ \mathrm{B}: {\mathrm{H}}_3{\mathrm{BO}}_3 \\ \mathrm{C}: {\mathrm{H}}_3{\mathrm{BO}}_2 \end{gathered}$$

(Enter your correct answer as $\mathrm{A}, \mathrm{B} \mathrm{or} \mathrm{C}$)