What must be done after lighting a fusee?

Answer: B — Point it away from the body when displaying hand signals

When a fusee is lit, it serves as a signaling device, indicating a warning or alert to others in the vicinity. Pointing it away from the body when displaying hand signals is crucial for safety and visibility. This practice ensures that the light of the fusee can be effectively projected and seen, enhancing communication with any approaching trains or personnel. By holding it at a distance from the body, it minimizes the risk of accidental burns or injury. In contrast, immediately throwing it away or hiding it from passengers does not utilize the intended purpose of the fusee, which is to signal. Leaving it on the train could also present safety hazards, as it may potentially ignite or cause confusion. Thus, the appropriate action after lighting a fusee is to point it away from the body to ensure safe and clear signaling.