The correct answer is A) All electrical equipment within 10 feet horizontally must be explosion proof or intrinsically safe. This is the correct answer because the handling of dangerous cargoes in bulk requires strict safety measures to prevent the risk of explosion or fire. The National Fire Protection Association (NFPA) standards, which are incorporated into the US Coast Guard regulations, require that all electrical equipment within a 10-foot horizontal radius of the cargo tanks must be designed to be explosion-proof or intrinsically safe to minimize the potential for ignition sources. The other answer choices are incorrect because they do not accurately reflect the specific regulations for the handling of dangerous cargoes in bulk on a cargo vessel.