Drummer Produces Two Products, a and B

Drummer produces two products, A and B. The following information is available for these two products:

-If a maximum of 10,000 units of A and/or B can be sold, it is best to

A) produce B only.
B) produce A only.
C) produce 2,500 units of A and 7,500 units of B.
D) produce 5,000 units of A and 5,000 units of B.