Answer:
c. will have a dual price of zero.
Step-by-step explanation:
When solving a linear equation with constraint that means not a balanced equation, we introduce a slack variable that is almost equal to zero, in order to balance the equation.
In that case the slack variable can have positive or negative value depending upon equation, but it does equal to almost zero.
Thus, it can have dual shadow value almost equal to zero, as the value is not considered.