Final answer:
Belgian expansion in the Congo serves as an example of imperialism.
Step-by-step explanation:
Imperialism refers to the policy or practice of extending a nation's power and influence through territorial acquisition or by gaining control over the economy and political affairs of other countries. From the given options, Belgian expansion in the Congo serves as an example of imperialism. During the late 19th and early 20th centuries, Belgium colonized the Congo region in Africa, exploiting its natural resources and dominating the local population for economic gain.
The creation of Germany as a nation-state does not necessarily represent imperialism, as it involved the unification of various German territories and peoples. The building of the HMS Dreadnought was a significant development in naval technology, but it does not directly relate to imperialistic practices. Similarly, the adoption of the machine gun by the German army was a military advancement, but it is not an example of imperialism.
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