The chemical equation for the combustion of propane can be represented as,

1 mol propane requires 5 mol oxygen for complete reaction to produce 3 mol carbon dioxide and 4 mol water.
Mass of propane = 25.0 g
Mass of oxygen = 90.7 g
The total mass of reactants = 25.0 g + 90.7 g = 115.7 g
According to Law of conservation of mass, the total mass of reactants will be equal to the total mass of products formed in a chemical reaction.
Therefore, here the mass of water and carbon dioxide will be 115.7 g
Correct answer: a. 115.7 g