A compound is formed by elements of $\mathrm{X},\mathrm{Y}$ and $\mathrm{Z}$. Atoms of $\mathrm{Z}$ (anions) make $\mathrm{FCC}$ lattice. Atoms of $\mathrm{X}$ (cations) occupy all the octahedral voids. Atoms of $\mathrm{Y}$ (cations) occupy $\frac{1}{3}\mathrm{rd}$ of the tetrahedral voids. The formula of the compound is:

• Correct answer
  A

  ${\mathrm{X}}_3{\mathrm{Y}}_2{\mathrm{Z}}_3$
• B

  ${\mathrm{X}}_2\mathrm{YZ}$
• C

  ${\mathrm{XY}}_2\mathrm{Z}$
• D

  ${\mathrm{X}}_2{\mathrm{Y}}_2\mathrm{Z}$

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