A Campaign Manager for a Political Candidate Must Arrange the Shipment

Multiple Choice

A campaign manager for a political candidate must arrange the shipment of 150 cartons of campaign buttons from three button producers to three campaign headquarters.The supplies and demands,and the per-carton transportation costs,are shown below: Which of the following is a constraint for the suppliers (button producers) ?

A) 2X11 + 5X12 + 6X13 ≤ 50
B) 9X11 + 3X12 + 7X13 = 50
C) X11 + X12 + X13 ≤ 50
D) X11 + X21 + X31 = 20
E) All of the choices are correct.