An equilibrium mixture of NO(g), O2(g) and NO2(g) is allowed to expand from 1.0 to 2.0 L at a constant temperature. Given that 2 NO(g) + O2(g) <=> 2 NO2(g) which of the following statements is correct?
a. The concentrations of all three gases are unchanged.
b. The value of Kp would decrease.
c. The number of moles of NO2 would increase.
d. The number of moles of O2 would increase.
e. The number of moles of all three gases are unchanged.