Which equations represent the incomplete combustion of methane?

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

II.     \({\text{C}}{{\text{H}}_4}{\text{(g)}} + {\text{1}}\frac{1}{2}{{\text{O}}_2}{\text{(g)}} \to {\text{CO(g)}} + {\text{2}}{{\text{H}}_2}{\text{O(g)}}\)

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

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

C