Answer: Option C
Step-by-step explanation:
Since this question asks for complete combustion we can rule out options A and D. CO₂ is not made because the carbon was not fully oxidized, so we only have CO.
Next, we need to find which option, between option B and option C, is a balanced reaction. Right away, we can see that on the left side option B has 3 carbon and 4 carbon on the right. This means that option B isn't balanced.
Lastly, we will confirm that option C meets all the requirements to be the correct answer. It is a complete reaction, with a product of CO₂ and not CO. We have 3 carbons on both sides, 8 hydrogens on both sides and 10 oxygens on both sides. Option C is correct.
I have attached a visual for this problem as well.