Which of the following is true about sensitivity analysis excel?

a. sensitivity reports can be generated for all types of solver methods
b. reduced cost will always be 0 for a decision variable that has a non-zero value in the optimal solution
c. reduced cost shows how much the objective function value will change with a unit change in the right hand side of a constraint
d. shadow price shows how much the objective function value will change with a unit change in the decision variable coefficients