Step 1: Understanding the function argument.
The “function argument” seeks to identify the proper function (telos) of a thing in order to understand its nature and excellence.
Step 2: Philosophical origin.
This argument is central to Aristotle’s ethical philosophy, particularly in his work {Nicomachean Ethics}.
Step 3: Application of the argument.
Aristotle used the function argument to explain that the good life for humans is one that fulfils the distinctive human function, i.e., rational activity.
Step 4: Conclusion.
Therefore, the correct answer is (A) Aristotle.