What distinguishes interrupt$-$driven I$/$O from programmed I$/$O$?$

a$.$

In programmed I$/$O$,$ interrupts are not used.

b$.$

In interrupt$-$driven I$/$O$,$ the CPU is actively engaged in data transfer.

c$.$

Programmed I$/$O operates without the CPU.

d$.$

Interrupt$-$driven I$/$O does not use the system bus.