Fort Sill, Altus Air Force Base, and __________ are military institutions that demonstrate the long-standing importance of the federal military to Oklahoma’s economy.

Vance Air Force Base is in Enid, Oklahoma, and is another major federal military institution in the state. Sheppard and Lackland Air Force Bases are in Texas, while “Enid Air Force Base” is not the installation’s official name. The correct choice is Vance Air Force Base.

AI-written and checked against the verified answer.