Why must baggage or freight carried on a bus be secured?

Answer: C — So any door or window can be used in an emergency

The requirement to secure baggage or freight carried on a bus primarily relates to safety concerns in emergency situations. When bags and freight are unsecured, they can become projectiles during sudden stops or accidents. In the event of an emergency that necessitates the use of all available exits, the presence of unsecured items could block doors or windows, thereby hindering the evacuation of passengers. Ensuring that all items are properly stowed and secured allows for quick and safe egress, which is critical in a passenger transport scenario. Other considerations, while they are important for overall vehicle operation and safety, do not directly address the urgency and potential consequences of emergency situations in the same manner.