A Manufacturing Firm Has Four Plants and Wants to Find

A manufacturing firm has four plants and wants to find the most efficient means of meeting the requirements of its four customers. The relevant information for the plants and customers, along with shipping costs in dollars per unit, are shown in the table below:
$$\text{Customer (requirement) }\\\begin{array} { l c c c c } &&Customer ~2 &Customer ~3& Customer ~4\\\text { Factory (capacity) }&\text{ Customer } 1 ( 125 ) & ( 150 ) & ( 175 ) & ( 75 ) \\ A ( 100 ) & \$ 15 & \$ 10 & \$ 20 & \$ 17 \\ \mathrm {~B} ( 75 ) & \$ 20 & \$ 12 & \$ 19 & \$ 20 \\ \mathrm { C } ( 100 ) & \$ 22 & \$ 20 & \$ 25 & \$ 14 \\ \mathrm { D } ( 250 ) & \$ 21 & \$ 15 & \$ 28 & \$ 12 \end{array}$$
Note: This question requires Solver.
Formulate the problem in Solver and find the optimal solution. What is the optimal quantity to ship from Factory B to Customer 3?

A) 25 units
B) 50 units
C) 75 units
D) 100 units
E) 125 units