Answer:
I think adding a catalyst
Step-by-step explanation:
From what I found, any of the first 4 don't work, reducing the concentrations of reactant molecules just decreases the chances of it reacting, decreasing the temperature does more or less the same, as it takes away energy, decreasing the surface area of the particles does more or less nothing in this situation, but for a reaction to occur, you need to add energy, which only the catalyst does. good luck!