The correct answer is A) weighed. During a Coast Guard inspection, all carbon dioxide (CO2) fire extinguishers aboard will be weighed to ensure they meet the required weight specified by the manufacturer. This is done to verify that the extinguisher contains the proper amount of CO2 to effectively fight a fire. Weighing the extinguishers is the standard procedure, as it is a quick and efficient way to check their charge without having to discharge and recharge them (option B) or send them to an approved service facility (option C). Option D, checking for pressure loss, is not the correct procedure for CO2 extinguishers, as they do not have a pressure gauge like dry chemical extinguishers.