The equilibrium , `SO_2Cl_2(g) hArr SO_2(g)+Cl_(2)(g)` is attained at `25^@C` in a closed container and an inert gas , helium , is introduced. Which of the following statement is are correct ?
A. Concentrations of `SO_2,Cl_2 and SO_2Cl_2` are changed
B. No effect on equilibrium
C. Concentrations of `SO_2` is reduced
D. `K_p` of reaction is increasing