${\mathrm{Na}}_2{\mathrm{B}}_4{\mathrm{O}}_7\cdot 10{\mathrm{H}}_2\mathrm{O}\text{ is correctly represented as }$

• A

  $2{\mathrm{NaBO}}_2\cdot {\mathrm{Na}}_2{\mathrm{B}}_2{\mathrm{O}}_2\cdot 10{\mathrm{H}}_2\mathrm{O}$

• B

  ${\mathrm{Na}}_2\left[{\mathrm{B}}_4{\mathrm{O}}_5(\mathrm{OH}{)}_4\right]\cdot 8{\mathrm{H}}_2\mathrm{O}$

• C

  ${\mathrm{Na}}_2\left[{\mathrm{B}}_4{\left({\mathrm{H}}_2\mathrm{O}\right)}_4{\mathrm{O}}_7\right]\cdot 6{\mathrm{H}}_2\mathrm{O}$

• D

  Na₂B₅O₈.4 H₂O