Which Statement About Appointment Scheduling Is NOT True

Which statement about appointment scheduling is NOT true?

A) Most clinics schedule an appointment every 15 minutes.
B) A walk-in is the name for a client who comes to practice without an appointment.
C) More complicated cases should be scheduled for the end of the day so that hospitalized patients can be treated in the morning.
D) The client should be called the day before an appointment to confirm.