A 5-node ZooKeeper ensemble suffers a network partition that splits it into Group A (2 nodes) and Group B (3 nodes). Which statement correctly describes the system's behavior?

1. A Both groups continue serving writes to prevent data loss, potentially causing a divergent split-brain state.
2. B Group A stops serving writes. Group B (Majority) elects/retains its leader and continues serving writes normally.
3. C The entire ensemble enters 'safe mode' and rejects all operations (read and write) until all 5 nodes are reachable.
4. D Group B continues as leader, but only for reads; all writes are blocked until Group A is also available for acknowledgment.