The correct answer is A) if he can do so without serious danger to his vessel or to individuals on board. This is correct based on the U.S. Coast Guard regulations regarding the duties of the master or person in charge after a collision or accident. The regulations state that the master must render assistance to those affected, but only if it can be done without serious danger to their own vessel or crew. The master is not required to put their own vessel or crew at undue risk in order to render assistance. The other options are incorrect because B) would require the master to render assistance without regard to any danger, which is not the standard; C) would require no risk at all, which is an unrealistic standard; and D) would only require assistance if it can be done without undue delay, which is a less stringent requirement than the regulation.