The main idea here is that the Rehabilitation Act of 1973 established vocational rehabilitation services and counseling specifically to help people with disabilities who face employment barriers move toward and maintain work. These services are aimed at adults with physical or mental disabilities who can benefit from supports like counseling, training, and job placement to become employed or regain employment. That makes the described group—employable adults with severe physical or mental disabilities—the best fit, because the act focuses on providing tailored employment assistance to those whose disabilities create barriers to work. The other options don’t align with this targeted purpose: the act isn’t designed to serve all students with disabilities, nor is it limited to senior citizens, nor is it available to anyone seeking vocational training without regard to disability or potential benefit from VR services.