3. (a) Define a Nash equilibrium. (3 marks) (b) The game of Chicken is played by two macho teens who speed toward each other on a single-lane road. The first to veer off is branded the chicken, whereas the one who does veer gains peer- group esteem. Of course, if neither veers, both die in the resulting crash. Payoffs to the Chicken game are provided in the following table: Teen 2 Teen 1 Veer Does not Veer Veer (2,2) (1,3) Does not (3,1) (0,0) Veer (i) Draw the extensive form. (2 marks) (ii) Find the pure-strategy Nash equilibrium or equilibria. Give adequate explanation of your answer. (4+ 3 = 7 marks)