Final answer:
A Sailor in the STA-21 program must attend a university with a Military Science Program, essential for their leadership and military education as future commissioned officers.
Step-by-step explanation:
A Sailor selected for the Seaman to Admiral (STA-21) program is required to attend a university that offers Military Science Programs. The STA-21 program is a commissioning program within the United States Navy that aims to provide opportunities for enlisted personnel to become commissioned officers. Attending a university with a Military Science Program as part of ROTC (Reserve Officers' Training Corps) is essential, because it prepares candidates with the leadership skills and military education necessary for their future roles. Therefore, the correct answer is D) Military Science Programs.