What is an Environment Pointer $($EP$)?$ It is a pointer to the top location of the rune$-$time stack. It is a pointer to the base address of the activation record instance of the calling program unit in the run$-$time stack. It is a pointer to the base address of the activation record instance of the currently executing subprogram in the run$-$time stack It is a pointer to the base address of the activation record instance of the main function in the run$-$time stack. Clear my selection