Answer:
Four buttons are needed for this application
Explanation:
The user activities such as entering the user name, subject, preferred appointment time and phone number are done using a text box. Typically, a text box is used to display, or accept as input, texts from the user.It is a graphical control element intended to enable the user to input text information to be used by the program.
Only activities such as submission of requests, Printing appointment request, clearing the screen and exiting the application, will require the user to click on a button. The buttons should be properly labelled and made to function on click/trigger.