单项选择题

若反应气体都是理想气体,反应平衡常数之间有Ka=Kp=Kx的反应是:()
(1)2HI(g)=H2(g)+I2(g);
(2)N2O4(g)=2NO2(g);
(3)CO(g)+H2O(g)=CO2(g)+H2(g);
(4)C(s)+CO2(g)=2CO(g)

A.(1)(2)
B.(1)(3)
C.(3)(4)
D.(2)(4)