One mole of N2Oo) is kept in a closed container along with gold catalyst at 450 Kunder one atmosphere. It is heated to 900 K when it dissociates to N2o) and O2lo) giving an equilibrium pressure of 2.4 atm. The degree of dissociation of N2O(g) is (A) 20% (B) 40% (C) 50% (D) 60%