Identify the choice that best completes the statement. Economic models:.
a. cannot be useful if they are based on false assumptions
b. were once thought to be useful, but that is no longer true.
c. must incorporate all aspects of the economy if they are to be useful.
d. can be useful, even if they are not particularly realistic.

The correct answer is the option D: Can be useful, even if they are not particulary realistic.

Explanation:

To begin with, the economic models are believed to have been made decades ago by classical economists like Adam Smith and David Ricardo so that explains that nowadays there is a whole different context around the world and the economy of every country and about how those country see and treat they economics objectives so that means that even though that the models created years ago are not quite realistic nowadays and everything falls out when it comes to the real world and the practice, those models can be quite useful in order to understand how some things in the economy works.