a) For handling an I/O operation, there are two possible approaches: synchronous I/O and asynchronous I/O. State the difference of these two approaches.

b) The simplest method for performing input and output is Programmed I/O (PIO).

1. State one disadvantage of PIO
2. Name one usage of PIO

c) What is the difference between polling and polled interrupt processing?

d) State and explain any THREE primary uses of interrupt.