a) In multitasking Operating Systems, there are two types of multitasking such as the "Preemptive Multitasking" and the "Cooperative Multitasking". Describe the two mentioned multitasking type and give a reason which of the two is better.
b) Explain the four main functions of an operating system.
c) What is a modem and give two different kinds of modems.
d) There are several different types of threats concerning computer security. Explain two of such threats.