It would be systematic because your not persuading them to do anything and assertive is about your personality. Systematic means to do something according to a plan or system.
The 'Call to action" statement is where you engage your reader it should inspire, educate, and it should be able to win over the reader to your "Cause".
Hmm, I would probably go with B. While both I think are correct, B makes a little more sense.
