When an adjustable nozzle is not in use, it should be set to which position?

Answer: B — Fog position

When an adjustable nozzle is not in use, it should typically be set to the fog position. This setting allows for a wide dispersal of water, which is ideal for various firefighting scenarios as it can quickly cool the environment and minimize the risk of flare-ups. The fog pattern also helps to reduce the velocity of water flow and can create a vapor barrier, which is beneficial in controlling heat and smoke during operations. Setting the nozzle to fog position when not in use ensures that it is ready for immediate deployment while optimizing safety and effectiveness. This position protects the nozzle from damage and prevents blockage, as it is not closed off completely. Other options, such as the straight stream or wide spray positions, may not adequately protect the nozzle or provide the best coverage and cooling effects when not actively fighting a fire. Additionally, the closed position would not allow for immediate use, as the nozzle would require adjustment to open it for functioning.