A client is on trial for a violent offense and the defense claims the client was legally insane at the time of the act. According to the M'Naghten Rule, which criterion must be met for the insanity defense to be valid?

Choice A reason: The M’Naghten Rule requires proof that, due to mental illness, the person did not understand the nature of the act or could not distinguish right from wrong at the time of the offense. This is the key standard used in many jurisdictions for insanity defenses. Choice B reason: Having a history of mental illness alone is not sufficient; the rule focuses on the client’s mental state during the offense, not prior diagnoses. Choice C reason: Being driven by uncontrollable impulses is not part of the M’Naghten criteria. This falls more under the “irresistible impulse” test, which is separate. Choice D reason: Intoxication, even if it impairs judgment, does not qualify under the M’Naghten Rule. Voluntary substance use generally excludes insanity defenses.