這兩題出自中興103年資管所計概考題，不知道是自己基本功差還是題目含糊
總有些不確定...
a privileged instruction may be executed only while the hardware is
in kernel mode. Which of the following statments is LEAST likely to
be a privileged instruction?
(A) An instruction that sends output to a printer
(B) An instruction that modifies a memory management register
(C) An instruction that halts the CPU
(D) An instruction that resets the computer's time-of-day clock
(E) An instruction that reads the computer's time-of-day clock
據我所知privileged instruction是指那些容易造成系統危險的指令，
因此要在kernel mode執行，通常對硬體進行操作的指令都是特權指令
這題我是猜E，不知道判斷有無錯誤

第一題你的想法應該沒錯，只有那個不會改變系統狀態