Suppose that two firms compete simultaneously in quantities. The inverse demand function is given by P = 12 - Q where Q = Q1 + Q2 is the sum of the quantities produced by firms 1 and 2 respectively. Assume also that these firms have NO COSTS. If firm 2 produces 2, 4 and 6 units, what is the optimal quantity that must be produced by firm 1
a) 4, 3 and 2 units respectively
b) 6, 5 and 4 units respectively
c) 5, 4 and 1 units respectively
d) 5, 4 and 2 units respectively
e) 5, 4 and 3 units respectively