15. Suppose the reaction system 2HI(g)⇌H2(g) + I2(g) has already reached equilibrium. Which of the following statements correctly predict the effect of each change on the equilibrium position? (A) Additional H2(g) added to the system will shift to the right to obtain the equilibrium. (B) As an exothermic reaction, the system will shift to the right to attain the equilibrium when increasing the system temperature. (C) When iodine gas is removed, the system will shift to the left to achieve the equilibrium. (D) Addition of argon gas into the reaction system will shift to the right to achieve the equilibrium. (E) When volume of the reaction container is doubled, the change will have no effects on its equilibrium.