Need help as soon as possible please and thank you :) Given the reaction at equilibrium:

2SO2 (g) + O2 (g) <=> 2SO3 (g) + 44 Kcal

Which change will increase the concentration of SO3 (g) ?

Select one:
a. increasing the volume of the reaction vessel
b. decreasing the pressure
c. increasing the temperature
d. increasing the concentration of O2 (g)
e. decreasing the concentration of SO2 (g)