The rate of reaction depends on various factors such as pressure, temperature, and the concentration of the compounds involved in the reaction.
Regarding the concentration, when the concentration of the reactants increases, the reaction moves towards the products. And when the concentration of the products increases, it will move towards the reactants.
So if we want the rate of reaction to increase, that is to say, that we have more products, the concentration of the reactants must be increased, be it sulfur or oxygen.
Therefore, the answer will be:
Answer: 4. You added more O2 to