In Microsoft Outlook, there are differences between appointment and event. Appointment is defined as an activity that you schedule in your calendar which does not involve other people. Appointments can be scheduled to a certain duration in a day. Event is defined as an activity that you do with other people which lasts from 24 hours to longer.
Thus, from these descriptions, the best answer to the question is (C) appointments have a start and end time of day, and events do not.
