What is the enthalpy of combustion of butane in kJ mol⁻¹?

2C₄H₁₀(g) + 13O₂(g) → 8CO₂(g) + 10H₂O(l)

\[\begin{array}{*{20}{l}} {{\text{C(s)}} + {{\text{O}}_2}{\text{(g)}} \to {\text{C}}{{\text{O}}_2}{\text{(g)}}}&{\Delta H = x{\text{ kJ}}} \\ {{{\text{H}}_2}{\text{(g)}} + \frac{{\text{1}}}{2}{{\text{O}}_2}{\text{(g)}} \to {{\text{H}}_2}{\text{O(l)}}}&{\Delta H = y{\text{ kJ}}} \\ {4{\text{C(s)}} + {\text{5}}{{\text{H}}_2}{\text{(g)}} \to {{\text{C}}_4}{{\text{H}}_{{\text{10}}}}{\text{(g)}}}&{\Delta H = z{\text{ kJ}}} \end{array}\]

A.     4x + 5y − z 

B.     4x + 5y + z 

C.     8x + 10y − 2z 

D.     8x + 5y + 2z

A