${\mathrm{Al}}_2{\mathrm{O}}_3$ was leached with alkali to get $\mathrm{X}.$ The solution of $\mathrm{X}$ on passing of gas $\mathrm{Y},$ forms $\mathrm{Z}.$

$\mathrm{X},\mathrm{Y}$ and $\mathrm{Z}$ respectively are

• A

  $\mathrm{X}=\mathrm{Al}{\left(\mathrm{OH}\right)}_3,\mathrm{Y}={\mathrm{CO}}_{2^{\text{'}}}, \mathrm{Z}={\mathrm{Al}}_2{\mathrm{O}}_3$
• B

  $X=\mathrm{Na}\left[\mathrm{Al}{\left(\mathrm{OH}\right)}_4\right],\mathrm{Y}={\mathrm{SO}}_2, \mathrm{Z}={\mathrm{Al}}_2{\mathrm{O}}_3$
• C

  $\mathrm{X}=\mathrm{Al}{\left(\mathrm{OH}\right)}_3, \mathrm{Y}={\mathrm{SO}}_2, \mathrm{Z}={\mathrm{Al}}_2{\mathrm{O}}_3·{\mathrm{xH}}_2\mathrm{O}$
• Correct answer
  D

  $X=\mathrm{Na}\left[\mathrm{Al}{\left(\mathrm{OH}\right)}_4\right], \mathrm{Y}={\mathrm{CO}}_2, \mathrm{Z}={\mathrm{Al}}_2{\mathrm{O}}_3, x{\mathrm{H}}_2\mathrm{O}$

Hence, the correct answer is option: 'D'.