In the nineteenth century, Indian nationalism developed in response to

Indian nationalism developed in response to British colonization.

Explanation:

Indian nationalism formed its "roots" during the 19th century. The formation of a sense of national belonging and the struggle for independence will last until the end of the Second World War. Indian nationalism is characteristic because it was unique despite great antagonisms in terms of language, religion, and ethnicity. The impetus for national unification was the British colonization of that tremendous Asian country.