Informal sector consists of own-account workers and enterprises employing fewer than 10 hired workers. A cycle-rickshaw puller (A) is self-employed - informal. A cook in a hostel with 9 hired workers (C) is below the 10-worker threshold - informal. A farmer on his own plot (E) is self-employed - informal. The civil engineer in a government enterprise (B) and the teacher in a school with 11 workers (D) are formal. Hence A, C, E.