Scenario​ : The average total cost to produce 100 cookies is​ $0.25 per cookie. The marginal cost is constant at​ $0.10 for all cookies produced. Refer to Scenario 1. The total cost to produce 50 cookies is:______.
A. ​$25.
B. ​$50.
C. ​$60.
D. ​$20.
E. indeterminate.