Which of the following is a good option for the decision maker when formulating and solving complex nonlinear programming models?

a. Formulating the problem as a linear model and considering the trade-off between a less rigorous formulation and an efficient solution
b. Formulating the problem as a nonlinear model and solving it using linear modeling approaches
c. Not using an optimization technique and saving on model building and solution costs
d. All of the above

A