The given reaction is exothermic reaction, hence, decreasing temperature is the favourable condition. The change in gaseous moles of products and reactants is negative, hence, increasing pressure is the favourable condition. Addition of reactants and removal of products are the favourable conditions. Catalyst only increase the speed of the reaction.
The yield of SO3 at equilibrium will be due to :
B. Increasing pressure
C. Adding more SO2
D. Adding more O2