What is log compaction in Kafka, and when is it useful?

What is log compaction in Kafka, and when is it useful?

• A. Log compaction deletes all messages older than a fixed time.
• B. Log compaction makes the log binary compressed.
• C. Log compaction preserves the latest value for each key by removing older records with the same key; useful for changelog topics and state reconstruction.
• D. Log compaction duplicates messages to another log.

Answer: (C)