Which of the following would be considered unemployed? a. Mark, laid off from his job as a bricklayer, returned to school full-time. b. Janice, a senior in college, started job hunting early in the hope that she would have secured a job by the time she graduates in May. c. Tim, a 13-year old high school student, is looking for a part-time job. d. Sarah, a stay-at-home mom who earned nearly $80,000 per year in her previous job