What played a more important role in distinguishing rulers from their colonial subjects in the imperialism of the nineteenth-century than in earlier instances of imperialism? a. race.
b. gender.
c. slavery.
d. political ideals

Option A, Race, is the right answer.

Explanation:

The race is a term used to indicate the grouping of humans on the basis of shared natural or social positions into classes usually seen as distinct by the community. This term began to signify the physical traits during the early phase of the 17th century. On the other hand, the term, imperialism is used to describe the policy of an extension of one country by conquering other countries generally by the means of force. The imperialist nations and leaders gave the very reason that they have "a duty to civilize the inferior races", thus they adopted the policy of imperialism.

explanation:

i have ni idea