Two firms compete in quantities. The aggregate inverse demand is given by P = 120 - 5(Q1 + Q2), where Q1 is the quantity of output produced by Firm 1, and Q2 the quantity of output produced by Firm 2. Firm 1 has a constant marginal cost of 5 per unit of output, Firm 2 a constant marginal cost of 10. Neither firm has fixed costs. Suppose Firm 1 chooses its quantity first, and then Firm 2 chooses its quantity, after having observed Firm 1's choice of quantity. Select all of the following statements that are true. Firm 1 choosing Q1 = 12 and Firm 2 choosing Q2(Q1) =5 for all Q1 is a subgame perfect equilibrium. Firm 1 choosing Q1 = 12 and Firm 2 choosing Q2(Q1) =5 for all Q1 is a Nash equilibrium. Firm 1 choosing Q1 = 8 and Firm 2 choosing Q2(Q1) =7 for all Q1 is a Nash equilibrium. Firm 1 choosing Q1 = 8 and Firm 2 choosing Q2(Q1) = 7 for all Q1 is a subgame perfect equilibrium