Which of the following best defines Hazard to Navigation, Markings, Obstruction, and Structures?

A) Any condition or situation that poses a threat or danger to the safe navigation of vessels, including natural or man-made obstacles.
B) The process of identifying and labeling potential dangers or obstacles in order to guide and warn navigators.
C) The act of intentionally blocking or hindering the movement of vessels in a waterway.
D) The physical components or facilities, such as bridges, piers, or buoys, that are used for navigation purposes.