If you simulate the environment mentioned in this lab, the oplog is never going to run out of space because of one write operation. All options listed under the question is in reference to this particular case. However, I will talk to the team and see if we can make any changes to the question to make it more clear.
Yes, what you have said is true that if the oplog has been overwritten before any node could replicate the instructions then in that case it would require manual intervention and an initial sync.
Hope it helps!
Please let me know if you have any other question.
Curriculum Support Engineer