Question 836 Deck General

The correct answer is A) at all locations where Class 1 explosive materials are being handled. This is because U.S. regulations require that "No Smoking" signs must be posted at all locations where Class 1 explosive materials are being loaded, unloaded, or handled on a vessel. This is a safety precaution to prevent accidental ignition of the explosives. The other answer choices are incorrect because they do not specify the locations where the "No Smoking" signs must be posted as per the regulations. The signs are not required in ladder wells, mess halls, or recreational rooms unless those are the specific areas where the Class 1 explosives are being handled.