Answer
d) is the correct answer.
Work Step by Step
Combustion involves the reaction of a compound with oxygen to produce carbon dioxide and water.
According to the law of conservation of mass, the sum of the masses of the reactants (burned compound and oxygen) is equal to the same of the products ($CO_2$ and $H_2O$).
Therefore, since oxygen is added, the sum of the masses of the products should be higher than the mass of the compound alone.
