What is the sum of all coefficients for the combustion of one mole of propane?

___ \({{\text{C}}_{\text{3}}}{{\text{H}}_{\text{8}}}{\text{(g)}} + \) ___ \({{\text{O}}_{\text{2}}}{\text{(g)}} \to \) ___ \({\text{C}}{{\text{O}}_{\text{2}}}{\text{(g)}} + \) ___ \({{\text{H}}_{\text{2}}}{\text{O(l)}}\)

A.     8

B.     12

C.     13

D.     15

C

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