Which of the following is an incapacity defense to crime?

• A. All of the above
• B. Age
• C. Insanity
• D. Intoxication

Answer: (D)

An incapacity defense is about the defendant’s lack of mental capacity to form the required mens rea at the time of the crime. Age can render someone unable to form intent, and insanity is a defense because a mental disease or defect can prevent understanding or appreciating the act. Intoxication fits the same idea in many contexts: if intoxication interferes with forming the necessary mental state, it can negate liability, especially for crimes requiring a specific intent or when intoxication is involuntary. Because intoxication directly impairs the mental state needed for the offense, it’s treated as an incapacity defense in this framing, which is why it’s selected here.