What one of the following is a commissioning source for the Marine Corps?

The answer is correct because the Marine Corps has several commissioning sources, and one of the primary pathways is through four-year colleges, specifically through programs such as the Platoon Leaders Class (PLC), Officer Candidate School (OCS), and the Naval Reserve Officers Training Corps (NROTC). These programs are designed to prepare and train college students and graduates to become commissioned officers in the Marine Corps.

The PLC allows students to attend training in the summer while completing their college education, and upon graduation, they are commissioned as Second Lieutenants. OCS is another method where candidates who have already completed their college education can attend a training program that prepares them for officer responsibilities. NROTC also provides a pathway for college students to receive military training while earning their degree, which leads to a commission upon graduation.

The other options represent different training programs but do not serve as commissioning sources for the Marine Corps in the same capacity. The Officer Development School primarily provides training for officers who are already commissioned. The Direct Commission Officer Course (DCOIC) is more focused on officers who are transitioning from civilian life into a commissioned role without going through the traditional pathways of collegiate programs. Lastly, the Limited Duty Officer Academy is aimed at providing further education and training to existing