The correct answer is D. travellers around the world.
A globetrotter is a person who travels extensively, especially around the world. The number of globetrotters has increased after the Second World War for a number of reasons. First, the war led to the development of new technologies that made travel easier and more affordable. Second, the war also led to the rise of a new middle class in many countries, which had the disposable income to travel. Third, the war also led to a decline in the stigma associated with travel, as people began to see it as a way to learn about different cultures and experience new things.
The other options are incorrect. Option A, foreign countries, is not a person. Option B, great persons, is a subjective term that could refer to a number of different things. Option C, people of importance, is also a subjective term that could refer to a number of different things.