Which of the following must the electronic chart of an ECDIS display, as required by IMO/IHO?

Correct Answer: Option D — All of the above

IMO/IHO standards mandate that the ECDIS Display Base must contain essential navigational information to ensure safety. This includes hydrographic data, regulatory boundaries, and ferry routes, among other critical features. These elements are required to be permanently displayed to provide the navigator with a comprehensive view of the environment.