(1) It is no defense to a prosecution for criminal solicitation that the person solicited could not be guilty of the crime solicited because of:
(a) Criminal irresponsibility or other legal incapacity or exemption; or (b) Unawareness of the criminal nature of the conduct solicited or of the defendant's criminal purpose; or (c) Any other factor precluding the mental state required for the commission of the crime solicited.
(2) It is no defense to a prosecution for criminal conspiracy that a co-conspirator could not be guilty of the conspiracy or the crime contemplated by the conspiracy because of:
(a) Criminal irresponsibility or other legal incapacity or exemption; or (b) Unawareness of the criminal nature of the conspiracy or the conduct contemplated by the conspiracy or of the defendant's criminal purpose; or (c) Any other factor precluding the mental state required for the commission of the conspiracy or the crime contemplated by the conspiracy.
(3) A defendant cannot be convicted of conspiracy if all of his co-conspirators have been acquitted or discharged under circumstances amounting to an acquittal.