Final answer:
Proteins made on the rough ER are least likely to be found in the cytosol of the cell.
Step-by-step explanation:
The protein made on the rough ER of a cell is least likely to be found in the cytosol of the cell.
Ribosomes on the rough ER produce proteins that are destined for the cell membrane or to be secreted from the cell. These proteins are sequestered inside membrane-bound compartments and will never touch the cytosol. They are modified, packaged into vesicles, and transported to their respective destinations within the cell.
Therefore, the least likely scenario is for the protein made on the rough ER to be found in the cytosol.