Cynthia Horn worked for Knight Facilities Management-GM, Inc., in Detroit, Michigan, as a janitor. When Horn developed a sensitivity to cleaning products, her physician gave her a "no exposure to cleaning solutions" restriction. Knight discussed possible accommodations with Horn. She suggested that restrooms be eliminated from her cleaning route or that she be provided with a respirator. Knight explained that she would be exposed to cleaning solutions in any situation and concluded that there was no work available within her physician's restriction. Has Knight violated the Americans with Disabilities Act by failing to provide Horn with the requested accommodations? Explain.