Why must a driver verify that the security seals on the bus's fire extinguishers are intact during the pre-operational check?

1. To ensure the extinguisher is clean and polished
2. To confirm that the extinguisher has not been tampered with, discharged, and is fully ready for use in an emergency
3. Because union representatives will issue fines for missing seals
4. To check if the extinguisher is painted the correct shade of red