The Acme Chemical Company has some employees who work in a production plant and some who work in a sales office. The office workers get paid every Friday; however, the plant workers get paid for every fifth box of supplies that they complete. The plant workers are paid on a _____ schedule, whereas the office workers are paid on a ______ schedule. A) fixed interval; fixed ratio B) fixed ratio; fixed interval C) variable interval; variable ratio D) variable ratio; fixed interval