In a subroutine call, who should explicitly push parameters to the stack?

In a subroutine call, who should explicitly push the return address to the stack?

In a subroutine call, who should explicitly push the registers that will be modified in the subroutine to the stack?

In a subroutine call, who should explicitly push the local variables to the stack?

for the questions above is it the caller, callie, or does It occurs automatically when the call is made.