What is the difference between acting "purposely" with respect to a result and acting "knowingly" with respect to a result under the model penal code? question 4 options: a. to act purposely is to do something that requires planning, whereas to act knowingly is to do something, while aware of certain facts, which is unplanned. b. to act purposely is to do something by choice whereas to act knowingly is merely to do something consciously. c. to act purposely is to do something of one's own volition, whereas to act knowingly only requires that the defendant be aware of his action. d. to act purposely is to act with purpose, aim, or design to cause a particular result, whereas to act knowingly is to do an act conscious of the practical certainty of the results?