Final answer:
The incorrect statement about military professional responsibilities is 'Prioritizing Personal Gain,' as the focus should be on serving in accordance with military ethics and not self-interest.
Step-by-step explanation:
The statement NOT true regarding the professional responsibilities of military professionals is C) Prioritizing Personal Gain. The primary duties of military professionals include upholding the Constitution, obeying lawful orders, and respecting the chain of command. These responsibilities are essential to maintaining discipline, order, and effectiveness within the military. Prioritizing personal gain over these duties would be deemed unprofessional and contrary to military ethics.