It can be deduced from the text IV that

some of the historic events that took place in late 19th century and after World War II became key factors in the development of tourism.

the industry of tourism was already fully developed in late 19th century Britain.

the history of tourism shows that governments and tourist authorities were very aware of all its economic potential well before World War II.

travel has always been synonymous with what we nowadays call tourism.

ancient Romans could only afford to visit nearby seaside resorts.