Suppose a processor does not have any stack pointer registers, which of the following statements is true?
- It cannot have subroutine call instruction
- It cannot have nested subroutines call
- Interrupts are not possible
- All subroutine calls and interrupts are possible
I think answer is 2.
Reason- Because in nested subroutine calls, we push old subroutines into stack and point most recent call with stack pointer.
Please, explain which is the correct option. According to book the answer is 1.