What flag must be hoisted on the outboard halyard before beginning an ammunition handling evolution?

The correct flag to hoist on the outboard halyard before beginning an ammunition handling evolution is the Bravo flag. The Bravo flag, which is a solid red flag, is an international signal flag that indicates that a ship is involved in the handling of explosives or dangerous cargo. Hoisting this flag signifies to other vessels and harbor authorities that caution is required due to the potential hazards associated with the handling of ammunition. This procedure is crucial for ensuring safety during such operations, as it alerts personnel nearby of the increased risks and the need for adherence to safety protocols.

Other flags mentioned, such as Alpha, Charlie, and Delta, have different meanings and are not used to indicate ammunition handling. Therefore, the use of the Bravo flag specifically aligns with the regulations and safety measures governing the handling of dangerous cargo and explosives.