in multi-programmed systems, it is advantageous if some programs such as editors and compilers can be shared by several users.
Which of the following must be true of multi-programmed systems in order that a single copy of a program can be shared by several users?
I. The program is a macro
II. The program is recursive
III. The program is reentrant

A

I only

B

II only

C

III only

D

I, II and III