5. Firms 1 and 2 compete on quantity with some product differentiation. They each have zero cost of production (zero marginal cost, zero fixed cost), but firm 1 may advertise and incur related costs. Demand for firm 1 is P1 = 10-q1 -42 + A, where q, and q, are quantities for firms 1 and 2, and A is firm I's level of advertising. The cost of advertising is A?. Firm 2 does not advertise. Demand for firm 2 is P2 = 10-q1 - 92. Now suppose the game is dynamic. Firm 1 sets advertising A,, both firms observe A,, and then both firms simultaneously set quantities. c. Find the Nash Equilibrium in the quantity-setting subgame, after A, has been chosen. d. Given your previous answer, find the optimal A and the resulting quantities. e. Discuss why A is bigger or smaller in part (d) compared to part (b)