Which of the following is part of the MPC Test for insanity?

The correct answer involves the defendant's inability to appreciate the nature and wrongfulness of their actions. Under the Model Penal Code (MPC) test for insanity, a defendant can be excused from criminal liability if, at the time of the conduct, they had a mental disease or defect preventing them from understanding the nature of their act or distinguishing right from wrong. This is reflected in Option A, which accurately describes the essential component of the MPC test.

The MPC does not require a defendant to prove a layman's understanding of morality, nor does it call for evidence of a permanent mental illness or that the defendant had received treatment for insanity prior to the commission of the crime. The focus is on the defendant's mental state at the time of the offense, particularly their ability to appreciate their actions and the moral implications of those actions. This framework reinforces the principle that criminal responsibility is contingent on the mental capacity to understand whether one’s actions were lawful or not.