Final answer:
The recommended action by air bag manufacturers when a steering wheel must be displaced during extrication and the air bag has not deployed is to disconnect the battery cables to prevent accidental deployment. Therefore, the correct option in the final answer is B. Disconnect the battery cables.
Step-by-step explanation:
If the steering wheel must be displaced during extrication and the air bag has not deployed, air bag manufacturers recommend disconnecting the battery cables as per the provided options. This procedure is essential because it helps to prevent the accidental deployment of the airbag, which could result in additional injuries to the patient or rescuers.
When a vehicle is involved in a collision, airbags are designed to deploy and protect the occupants by spreading the force of the impact over a longer period of time, thus reducing the impact force and potential damage or injury.
It is critical to handle undeployed airbags with caution during an emergency situation. The other options provided, such as securing a long backboard across the steering wheel or striking the hub with a mallet, are not recommended practices and could be dangerous.
If the airbag were to deploy while attempting these actions, the consequences could be severe. Therefore, the correct option in the final answer is B. Disconnect the battery cables.