What is the main function of Oplog?

What is the main function of Oplog?
A . A persistent write buffer to coalesce bursts of random writes before destaging to the extend store
B . A memory cache to coalesce all writes before destaging to the extent store
C . A persistent write buffer to coalesce all writes before destaging to the extent store
D . A memory cache to coalesce bursts of random writes before destaging to the extent store

View Answer

Answer: A