Final answer:
The correct individual with the discretion to relieve someone from duty for a P.M. appointment for jury duty would be determined by an organization's specific guidelines or chain of command protocol, which is not provided in the query information.
Step-by-step explanation:
The question pertains to who has the discretion to relieve someone from duty for a P.M. appointment for jury duty. This seems to be connected to internal policies within a specific organization or agency, likely related to emergency services or the military, given the ranks mentioned. However, without explicit context from an organizational guide or manual, determining the correct answer is not possible based on the provided constitutional excerpt from Section 2 concerning the President's powers. In general, this decision would typically lie with the person's direct superior or someone authorized within the organizational structure to make such decisions on personnel matters, which could vary by institution.