Answer
C-ER, golgi, vesicles that fuse with the plasma membrane
Work Step by Step
For most proteins produced you can assume ER followed by Golgi. This is because the rough ER holds the ribosome that will create the polypeptide chain. It goes to the Golgi to be packaged and prepared for further transport. The statement in the question that says "protein that will be secreted by the cell" helps you know that the last part of the answer option is correct. Any protein that will leave the cell will only be able to do this by a transport vesicle fusing and merging with the plasma membrane.
