The correct answer is C) CaCl2
This process is also termed as ammonia recovery .
The calcium hydroxide is reacted with the ammonium chloride separated out of the carbonating tower by filtration:
Ca(OH)2(aq) + 2NH4Cl(aq) → CaCl2(aq) + 2H2O(l) + 2NH3(g)
The ammonia is recycled back into the process to form ammoniated brine.
Calcium chloride is formed as a by-product of the Solvay Process .