$\mathrm{SiCl}_{4}$ on hydrolysis forms ' $\mathrm{X}$ ' and $\mathrm{HCl}$. Compound ' $\mathrm{X}$ ' loses water at $1000^{\circ} \mathrm{C}$ and gives 'Y'. Compounds ' $\mathrm{X}$ ' and ' $\mathrm{Y}$ 'respectively are

• A

  $\mathrm{H}_{2} \mathrm{SiCl}_{6}, \mathrm{SiO}_{2}$
• B

  $\mathrm{H}_{4} \mathrm{SiO}_{4}, \mathrm{Si}$
• C

  $\mathrm{SiO}_{2}, \mathrm{Si}$
• Correct answer
  D

  $\mathrm{H}_{4} \mathrm{SiO}_{4}, \mathrm{SiO}_{2}$

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