Kate and Alice Are Small-Town Ready-Mix Concrete Duopolists

Kate and Alice are small-town ready-mix concrete duopolists. The market demand function is where P is the price of a cubic yard of concrete and Q^d is the number of cubic yards demanded per year. Marginal cost is $80 per cubic yard. The Cournot model describes the competition in this market. What is the amount of the deadweight loss?

A) $8,893.38
B) $6.67
C) $1,333,33
D) $4,446.69