Concept:In a neutral compound, the total charge must balance, so oxidation numbers sum to zero.Explanation:Oxidation numbers show the charge an atom would have if all bonds were ionic.A neutral compound has no overall charge.Therefore, the total positive oxidation numbers must equal the total negative oxidation numbers.So the sum of all oxidation numbers in a neutral compound is 0.For example, in H2O: 2(+1)+(−2)=0.Answer:The correct option is C. 0.