a) Device Controller i) Extracts information from the controller
register and store it in data buffer
b) Device Driver ii) I/O scheduling
c) Interrupt handler iii) performs data transfer
d) Kernel I/O subsystem iv)Processing of I/O request
a b c d
A) iii iv i ii
B) ii i iv iii
C) iv i ii iii
D) i iii iv ii