According to the recommended emergency instructions format, what action should be taken regarding the ventilation system when a fire is discovered aboard?

1. A. Increase ventilation to clear smoke from the affected compartment
2. ✓ Shut off the ventilation system and close hatches, ports, doors, ventilators, and louvers to cut off air supplyCorrect
3. C. Redirect ventilation airflow toward the fire to push smoke overboard
4. D. Maintain normal ventilation to prevent heat buildup in adjacent compartments