Final answer:
The Department of Veterans Affairs is responsible for increasing educational benefits for veterans who have served since the 9/11 terrorist attacks, under the provisions of the Post-9/11 GI Bill.
Step-by-step explanation:
The agency that increases educational benefits for veterans who have served since 9/11 is the Department of Veterans Affairs (b). After World War II, the Servicemen's Readjustment Act of 1944, commonly known as the GI Bill, was enacted to provide various benefits to returning war veterans. These benefits included unemployment compensation, low-interest loans for homes and businesses, and educational benefits such as tuition for college or vocational school. Following the 9/11 terrorist attacks, veterans' educational benefits have been updated and enhanced by the Post-9/11 GI Bill, managed by the Department of Veterans Affairs. This bill offers significant educational benefits to individuals who have served on active duty after September 10, 2001.