The Boxer Rebellion broke out in China in the last years of the nineteenth century and was eventually crushed by the combined efforts of local government administrators and the European powers in 1900. The rebellion broke out in China due to anger directed at the growing influence of European powers in Chinese affairs.

Many European nations and empires practiced colonialism, the act of colonizing other lands - often destroying the native cultures already existing there. This was usually done to take advantage of the resources the land contained, or to simply spread an empire's global influence. The other answers are incorrect because they refer to other political processes.

European leaders met in Berlin in 1884 to decide which European nations would be able to colonize which regions of Africa. Many of the boundaries they set were drawn arbitrarily, ignoring the existing ethnic and cultural boundaries of the people who already lived there.

Marxism focuses on the economic class struggle between the rich and the poor. Its ideology does not provide a motivation for Imperialism. All the other choices are motivating factors for Imperialism.

Colonizing another country provides access to their natural resources, an available and cheap source of labor from its inhabitants, and a market to which to sell manufactured goods, all of which contribute to a favorable balance of trade.

Ethnocentrism is the belief that one's culture is superior to others. Europeans justified Imperialism by stating they were "civilizing" inferior cultures by introducing them (sometimes by force) to European language, culture and religion.

When a country becomes imperialistic (an imperial power, or ruler over large territory), they take control over another country or people's economy (money/trade), social (their culture/religion/language), and political (government/leaders/rulers/laws) areas or ways of life. Often, a country takes control in order to take advantage of natural resources in an attempt to make more money and become all-powerful.

Colonialism is achieved when a country only settles a territory or takes advantage of its commerce, or trade. Colonialism does not intend to take control of the territory as a whole like imperialism, which gain control of much, much more. In a colony, the people native to the area still have control of many aspects of their lives, whereas territories of an empire are essentially absorbed into the mother country.

Social Darwinism was a theory developed by Herbert Spencer, a social engineer pre-dating Charles Darwin's evolution theories. Spencer coined the phrase "survival of the fittest", meaning those that are the most fit or able should, and will, survive compared to those that are weaker.

To help justify the complete take over of other civilizations, imperialists argued that they were the more fit members of the human race and everyone else were weak and did not deserve to survive, have power/authority, or identity.

The Triangle Trade included three major passages across the Atlantic Ocean between the years 1600-1800, creating the shape of a triangle between Europe, Africa, and North America. The good listed in the question (especially raw goods, and slaves) were traded along these routes and colonial powers came to count on this trade in their economies.

Ultimately, a country would pay for its imports by way of its exports (an exchange of goods).

King Leopold II of Belgium only gained control of a small piece of Africa (Belgian Congo), and he maintained support from his subjects at home through deception. King Leopold II portrayed himself as an honorable missionary helping the natives, with a mission to better the quality of their lives. In reality, however, he gave leadership to individuals who allowed native workers who were slaves to be maimed or murdered as punishment for underperformance. Furthermore, under King Leopold's leadership, the native Congolese experienced what present-day experts would describe as genocidal acts (such as rape, violence, oppression, death, overall safety and liberty threatened).

One positive outcome from King Leopold's atrocious legacy is modern-day humanitarianism. Belgian subjects heard of his violations against human rights and activated against them.

England was at the front of the imperialism race because they had already developed their overseas colonies/territories by the beginning of the 19th century. They had colonies on every continent and maintained them over time, but the other European nations either had a late start, did not have as many colonies, or lost the colonies for various reasons (rebellion, for instance).

One reason England was able to become so powerful and maintain it colonies was because of wealth and man power.