Final answer:
The correct answer is option b) Expansion through military conquest.
Step-by-step explanation:
Russian imperialism in the 19th century had several distinctive characteristics when compared to other European powers. Under the leadership of the Tsars, Russia expanded its territorial reach through military conquest into Central Asia and elsewhere. Often, this expansion policy aimed at incorporating new territories directly into the Russian Empire.
Unlike some European powers, Russia did not always emphasize cultural assimilation as much as territorial expansion. The Russian Empire governed a vast array of ethnic groups, languages, and religions. Many of these groups were permitted to maintain aspects of their own culture, so long as it did not challenge the central authority of the Tsar.
Despite some elements of economic exploitation, Russia's colonial practices were not characterized by the kind of systematic resource extraction or trade monopolies that were seen in other empires. Its largely agricultural economy and later development of railroads tied the newly acquired territories economically to the heart of Russia.
Russia's approach to imperialism was therefore distinct because it focused on territorial expansion and integration, rather than purely economic exploitation or cultural dominance. This set the stage for the complex multiethnic composition of both the Russian Empire and later the Soviet Union.