Delayed members apply operations from the _______ on a delay.

delayed-members-apply-operations-from-the-on-a-delay

Delayed members apply operations from the _______ on a delay.

A. oplog

B. log

C. mlog

D. none of the mentioned

I had been asked this question at a job interview.

My query is from Master Slave Replication in section Replication Concepts, Processes and Replication Set of MongoDB

The correct answer is A. oplog

Explanation: Always prevent applications from seeing and querying delayed members.