Consider the following statements:-
1. Change program counter value
2. Change page table register context
3. Disable interrupt
4. Initiate I/o on a disk using memory mapped I/o
which of the above can be executed in only in system mode?
a.) 1,3,4
b)2,3,4
c.)1,2,3
d)2,4,1
Please give valid explanation with your answer.