For example, a combat medic, whose duties are to provide pre-hospital emergency treatment, may receive ASI training to become a cardiovascular specialist, a dialysis specialist, or even a licensed practical nurse. For commissioned officers, training includes pre-commissioning training, known as Basic Officer Leader Course A, either at USMA or via ROTC, or by completing OCS. After commissioning, officers undergo branch-specific training at the Basic Officer Leaders Course B, (formerly called Officer Basic Course), which varies in time and location according to their future assignments. Officers will continue to attend standardized training at different stages of their careers. Collective training at the unit level takes place at the unit's assigned station, but the most intensive training at higher echelons is conducted at the three combat training centers (CTC); the National Training Center (NTC) at Fort Irwin, California, the Joint Readiness Training Center (JRTC) at Fort Polk, Louisiana and the Joint Multinational Training Center (JMRC) at the Hohenfels Training Area in Hohenfels and Grafenwöhr, Germany. ReARMM is the Army Force Generation process approved in 2020 to meet the need to continuously replenish forces for deployment, at unit level and for other echelons as required by the mission. Individual-level replenishment still requires training at a unit level, which is conducted at the continental U.S. (CONUS) replacement center (CRC) at Fort Bliss, in New Mexico and Texas before their individual deployment. Chief of Staff Milley notes that the Army is suboptimized for training in cold-weather regions, jungles, mountains, or urban areas where in contrast the Army does well when training for deserts or rolling terrain. Post 9/11, Army unit-level training was for counter-insurgency (COIN); by 2014–2017, training had shifted to decisive action training. Equipment The chief of staff of the Army has identified six modernization priorities, in order: artillery, ground vehicles, aircraft, network, air/missile defense, and soldier lethality. Weapons Individual weapons The United States Army employs various weapons to provide light firepower at short ranges. The most common weapon type used by the army is the M4 carbine, a compact variant of the M16 rifle, along with the 7.62×51mm variant of the FN SCAR for Army Rangers. The primary sidearm in the U.S. Army is the 9 mm M9 pistol; the M11 pistol is also used. Both handguns are to be replaced by the M17 through the Modular Handgun System program. Soldiers are also equipped with various hand grenades, such as the M67 fragmentation