Final answer:
By 1910, most of the world's population was part of an independent nation state or under the control of an empire, with the British Empire being a dominant force controlling about 25% of the world's surface.
Step-by-step explanation:
In 1910, most of the world's population belonged to an independent nation state or were under the control of an empire. The period before the 15th century saw a world comprised of empires, kingdoms, and chiefdoms. However, by 1500, the concept of nation-states began to take shape in Europe, with powers like Britain and France establishing their own nations. Over the centuries, particularly between the 15th and 19th, these European nation-states expanded their territories through colonization and by the 19th century, nationalism became a driving force in world politics, with European empires spreading across continents.
Empires like the British controlled vast territories, as illustrated by the phrase "the sun never sets on the British Empire", signifying its global reach by 1918. This period saw the diminishing power of land-based empires and the British Empire became a prominent example of imperialism, governing large parts of the world, including India, Africa, and parts of Asia and North America. Thus, by 1910, the correct answer is that most of the world's population was either part of an independent nation state or under the control of European empires.