In the legal maxim "actus non facit reum, nisi mens sit rea", actus reus stands for:

Guilty Act

The correct answer is Option (2) → Guilty Act

In the legal maxim "actus non facit reum, nisi mens sit rea," which translates to "an act does not make one guilty unless the mind is also guilty," actus reus refers to the guilty act or the physical act that constitutes the crime. It is one of the essential elements of a crime, along with mens rea, which is the guilty mind or criminal intent.