Answer: d. The main purpose of models is to gain a better understanding of the world.
Explanation:
The scientific models can be defined as the simulating artificial models that are designed in such a way so as to mimic the natural processes or natural phenomena that occur on earth or universe. These models helps in understanding, analyzing, learning, visualizing, quantifying, simulating the various natural processes that occur on earth. These can also be used to show the physical features of the universe.