Simulation is used for several reasons, including

A) model development is a fast process.
B) it is inexpensive.
C) the models are usually simple.
D) it can handle large and complex real-world problems.
E) it always generates optimal solutions.

Simulation is particularly useful in handling large and complex real-world problems, where it may not be feasible or practical to conduct experiments in the real world. Simulation allows researchers to test different scenarios and options without incurring the costs and risks associated with real-world experimentation. While simulation can be less expensive than real-world experimentation, it is not necessarily a fast or simple process, and it does not always generate optimal solutions.