What Would Happen If Cl₂ Is Added to the Following

Multiple Choice

What would happen if Cl₂ is added to the following system at equilibrium?
H₂(g) + Cl₂(g) 2 HCl(g)

A) The concentrations of both H₂ and HCl would remain the same.
B) The concentrations of both H₂ and HCl would increase.
C) The concentrations of both H₂ and HCl would decrease.
D) The concentration of H₂ would increase, but HCl would decrease.
E) The concentration of H₂ would decrease, but HCl would increase.