An application using Azure Cache for Redis is experiencing high CPU usage. Which Redis operation is most likely causing this?

1. A Simple GET/SET operations
2. ✓ B KEYS * pattern scan on a large keyspace (correct answer)
3. C PING health check
4. D TTL retrieval

Shortcut: KEYS * blocks the Redis server while scanning all keys, O(N) where N = total keys. Use SCAN with a cursor for non-blocking iteration on large keyspaces.