Bill Nielsen works as a graphic designer. He arrives at work at 7 a.m. and goes home at 3 p.m. One of Nielsen's co-workers who performs the same job as he does arrives at work at 10 a.m. and goes home at 6 p.m. Yet another co-worker arrives at 9 a.m. and leaves work at 5 p.m. From this brief description, you should realize that Nielsen's employer uses: Group of answer choices