Correct Answer : Option (D) :   Dissociative – recombination reaction of nitrogen and oxygen
                                                                                                                
                                                                                                                                                                        
                                                        Explanation : The reaction taking place below 9000 K for the formation of nitric oxide are dissociation reaction and bimolecular exchange reaction also known as shuffle reaction. They are as follows:
           O2 + M ? 2O + M
           N2 + M ? 2N + M
           NO + M ? N + O + M
           O2 + N ? NO + O
The first two reaction are the dissociation of oxygen and nitrogen molecule respectively. The third and the fourth equations are the shuffle reactions.