In the graphs you've just explored, what is Bobbie's economic profit if she produces 4 haircuts per hour and why does the 4th haircut lower her profit? Producing 4 haircuts per hour, Bobbie's economic profit is _______ and the 4th haircut lowers her profit because _______. A. $12; she can sell only 3 haircuts per hour B. $8; she can sell only 3 haircuts per hour C. $12; its marginal cost exceeds its marginal revenue D. $8; its marginal cost exceeds its marginal revenue