Describe why or why not the following instructions should be either privileged or not privileged:

(b) read the time from the system clock,
(c) free (or erase) memory,
(d) turn off interrupt handling,
(e) switch between user and privileged mode.

References
[1] Abraham Silberschatz, Peter Baer Galvin, and Greg Gagne.Operating system concepts. John Wiley
& Sons Inc, Hoboken, N.J., 8. ed. edition, 2009. ISBN 978-0-470-23399-3.

You can also use internet