[Talia59]

A linear programming spreadsheet model, in which the objective function (target cell) is maximized contains, among other constraints, a constraint of the form: E4>=E5, where cell E5 contains a constant and E4 depends on the values chosen for the decision variables. The shadow price associated with this constraint is
a. positive;
b. negative;
c. negative or zero;
d. positive or zero;
e. may be positive, negative or zero.