Answer: C. They were frightened by nationalist leaders and wanted to reduce their influence.
Explanation:
Conservatism refers to a belief in maintaining tradition which is why people who follow this belief try to resist change as they believe that it could be detrimental to the survival of society.
When nationalist movements started out in Europe and emphasized the need for a change in the way they were governed, conservatives were alarmed and tried to limit the influence these nationalists had as they preferred the old ways as well as the power they had. For instance Austria tried to limit the influence of Prussia but this failed and led to the creation of the current German state.