Which is true about topic compaction?

Log compactionensures that Kafka retains at least thelatest value per keyin a topic. Compaction happensin the backgroundand removes older records with the same keyin inactive log segments, not immediately.

From theKafka Documentation > Log Compaction:

“Kafka guarantees that thelast message for each keywill be retained in the log after compaction, even if earlier messages with the same key are deleted.”

So, D is correct. A is incorrect because compaction does not overwrite; it's a background process. B is incorrect—deletion is not immediate. C incorrectly suggests client-side hashmap behavior.