In which reaction will the entropy of the system increase significantly?

A.     ${\text{CaC}}{{\text{O}}_3}{\text{(s)}} \to {\text{CaO(s)}} + {\text{C}}{{\text{O}}_2}{\text{(g)}}$

B.     ${{\text{H}}_2}{\text{O(g)}} \to {{\text{H}}_2}{\text{O(l)}}$

C.     ${\text{HCl(g)}} + {\text{N}}{{\text{H}}_3}{\text{(g)}} \to {\text{N}}{{\text{H}}_4}{\text{Cl(s)}}$

D.     ${\text{NaOH(aq)}} + {\text{HCl(aq)}} \to {\text{NaCl(aq)}} + {{\text{H}}_2}{\text{O(l)}}$

A