For the equilibrium,

$2{\mathrm{SO}}_2\left(g\right)+{\mathrm{O}}_2\left(g\right)\rightleftharpoons 2{\mathrm{SO}}_3\left(g\right),\mathrm{\Delta H}=-198\mathrm{kJ}$

the equilibrium concentration of ${\mathrm{SO}}_3$ will be affected by

increasing the temperature at constant volume

adding helium to the reaction vessel at constant volume

adding more oxygen to the reaction vessel

doubling the volume of the reaction vessel