As opposed to Programmed I$/$O $($PIO$),$ Direct Memory Access $($DMA$)$ utilizes the following protocol to realize efficient data movement. Fill out Step $3$ which is missing:

OS initiates DMA transfer by telling the DMA engine where data lives in memory and how much data to copy, etc.

DMA copies the data from memory

$[???]$

The DMA controller raises an interrupt to resume the waiting process

Choice $1$ of $4$: The I$/$O transfer begins on the disk

Choice $2$ of $4$: CPU keeps polling in a while loop

Choice $3$ of $4$: CPU copies the data from DMA controller

Choice $4$ of $4$: DMA copies the data back to CPU