Ports such as Aden, Honolulu and Singapore, which grew up as stopping places for fuel, water and stores, are classified as

The correct answer is B, ports of call. In the age of coal and later of oil, long ocean voyages had to be broken at fixed points where a ship could take on fuel, fresh water and provisions, and settlements at those points grew into ports. Aden on the route through the Red Sea, Honolulu in the middle of the Pacific and Singapore at the Strait of Malacca all began in this way, and several later became great trading centres in their own right. A, entrepot ports are collection centres where goods are imported in order to be re-exported, such as Rotterdam and Copenhagen. C, packet stations are short-distance ferry ports for passengers and mail, such as Dover and Calais. D, out ports are deep-water ports built away from a parent port, such as Piraeus for Athens.