The compound formed when gypsum is dissolved in aqueous ammonium sulphate solution, is

• A

  $\mathrm{CaSO}_4 \cdot \mathrm{NH}_4 \mathrm{Cl} \cdot \mathrm{H}_2 \mathrm{O}$
• B

  $\mathrm{CaCl}_2 \cdot\left(\mathrm{NH}_4\right)_2 \mathrm{SO}_4 \cdot \mathrm{H}_2 \mathrm{O}$
• Correct answer
  C

  $\mathrm{CaSO}_4\left(\mathrm{NH}_4\right)_2 \mathrm{SO}_4 \cdot 2 \mathrm{H}_2 \mathrm{O}$
• D

  $\mathrm{CaCl}_2 \cdot \mathrm{NH}_4 \mathrm{Cl} \cdot 2 \mathrm{H}_2 \mathrm{O}$

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