State the required answer precisely and then provide proper explanation. It is not enough to provide one- word or one-line answers.
Which of the following instructions must be privileged, executable only in system mode?
Provide brief justification for your answer. Remember that we would like to place minimal constraints on the user, i.e., allow maximum flexibility. Analyze each case separately.
A) Clear a memory location (byte) to all zero bits.
B) Switch from user to monitor mode.
C) Turn off interrupts.
D) Read the clock.