For the reaction N₂O₄(g) ⇌ 2NO₂(g), Kp = 0.492 atm at 300 K. Kc for the reaction at the same temperature is __ x 10⁻². (Given: R = 0.082 L atm mol⁻¹ K⁻¹)
a) 2.25
b) 3.15
c) 4.82
d) 5.68