In multistage equilibrium conversion of SO2 to SO3 (2SO2 + O2 ⇌ 2SO3), the reverse reaction becomes appreciable at a temperature of 550° C. The percentage equilibrium conversion of SO2 to SO3 can be increased by ?

• A. Increasing the oxygen concentration
• B. Putting more quantity of V2O5 catalyst in the converter
• C. Removing some quantity of SO3 during intermediate stage
• D. Maintaining low temperature & pressure in the converter