About the crystalline form of Borax in correct statement is

• A

  $\text{ Tetra nuclear }\left[{\mathrm{B}}_4{\mathrm{O}}_5(\mathrm{OH}{)}_4^{-2}\right]\text{ unit }$

• B

  All boron atoms in the same plane.

• C

  $\text{ Equal number of }{\mathrm{Sp}}^2\text{ and }{\mathrm{Sp}}^3\text{ hybridized boron atoms. }$

• D

  One terminal hydroxide per boron atom.