(a) For purposes of this article, “informed consent” means that a person must knowingly and intelligently, without duress or coercion, and clearly and explicitly manifest his consent to the proposed organic therapy to the attending physician.
(b) A person confined shall not be deemed incapable of informed consent solely by virtue of being diagnosed as a mentally ill, disordered, abnormal or mentally defective person.
(c) A person confined shall be deemed incapable of informed consent if such person cannot understand, or knowingly and intelligently act upon, the information specified in Section 2673.
(d) A person confined shall be deemed incapable of informed consent if for any reason he cannot manifest his consent to the attending physician.