Which one of the following is true with regard to a CPU having a single interrupt request line and single interrupt grant line…??

Which one of the following is true with regard to a CPU having a single interrupt request line and single interrupt grant line…??

i) Neither vectored nor multiple interrupting devices is possible.
ii) Vectored interrupts is not possible but multiple interrupting devices is possible.
iii) Vectored interrupts is possible and multiple interrupting devices is not possible.
iv) Both vectored and multiple interrupting devices is possible.