Ans. is 'd' i.e., Rule of nine Criminal responsibility of insane is judged by following rules : 1. Mc Naughten rule (legal test or right or wrong test) : It states that an accused person is not legally responsible, if it is clearly proved that at the time of commiting the crime, person was suffering from such a defect of reason from abnormality of mind that he didn't know the nature and quality of act he was doing or that what he was doing was wrong i.e. a person is not responsible if he is not of sound mind. It is accepted in india as law of criminal responsibility and is embodied in section 84 1PC as - "nothing is an offence which is done by a person, who at the time of doing it, by reason of unsoundness of mind is incapable of knowing the nature of act, or that he is doing what is either wrong or contrary to law". 2. Doctrine of paial responsibility - If a person is suffering from some weakness or aberration of mind (though not completely insane), he is only paially responsible for his actions, e.g. obsession states or depressions. 3. Durhan rule- Accused is not responsible for the act, if his act resulted from mental disease or defect. 4. Currens rule- A person is not responsible if at the time of committing the crime, he did not have the capacity to regulate his conduct according to the requirements of law, as a result of his mental disease or defect. 5. American law institute test-Insane lacks the capacity to appreciate the wrongfulness of his conduct or to confirm to the requirements of law, therefore he is not responsible for crimes committed. 6. Norwegion system-No defendant considered insane or unconscious at the time of offence, may be punished