In a 2.000 L flask containing 2.0 moles of H2(g), 6.0 moles of I2(g), and 2.0 moles of HI(g) at equilibrium, which gas concentration(s) will change if more H2 gas is added?
a) Only H2(g)
b) H2(g) and I2(g)
c) H2(g), I2(g), and HI(g)
d) None of the gases