Which process is endothermic?

A.     \({\text{C}}{{\text{H}}_4}{\text{(g)}} + {\text{2}}{{\text{O}}_2}{\text{(g)}} \to {\text{C}}{{\text{O}}_2}{\text{(g)}} + {\text{2}}{{\text{H}}_2}{\text{O(g)}}\)

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

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

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

C