Whose permission must be obtained prior to de-smoking using the installed ventilation?

The correct response is obtaining permission from the Engineering Officer (EO) prior to de-smoking using the installed ventilation. In naval operations and similar contexts, the Engineering Officer is responsible for the safe operation of the ship's systems, including the engineering spaces and ventilation systems. De-smoking, which is the process of clearing smoke from a space, involves manipulating the ship's ventilation systems, and therefore, it requires the approval of the EO to ensure that it is done safely and effectively.

The Engineering Officer must assess the situation, considering the impact on the ship's environment, safety protocols, and the functionality of systems. Their authorization helps ensure that the de-smoking process does not inadvertently compromise safety or lead to hazardous conditions.