181009-M-SW691-0023 QUANTICO, Va. (Oct. 9, 2018) U. S. Marine officer candidates participate in an obstacle course at Officer Candidate School in Quantico, Va., Oct. 9, 2018. The candidates must go through weeks of rigorous training in order to become commissioned as U.S. Marine Corps officers. (U.S. Marine Corps photo by Lance Cpl. Hilario Martinez)