Which statement best describes the Ku Klux Klan?

The correct answer, which states that both "a" and "b" best describe the Ku Klux Klan, accurately reflects the organization's historical context and objectives.

The Ku Klux Klan, founded in the United States post-Civil War, indeed can be characterized as an international racist organization. While its primary activities and influence have been concentrated in the U.S., the ideology it promotes—white supremacy and racial segregation—has influenced and found echoes in other far-right movements globally. This aligns with the first part of the statement.

Additionally, the Klan was created with the intention of promoting racial solidarity specifically among white Americans and Europeans, particularly in response to the Reconstruction era and the integration of formerly enslaved individuals into American society. Thus, the second part of the statement accurately highlights the Klan's agenda of fostering a cohesive identity predicated on race among white individuals.

In summary, both descriptions accurately capture the essence and motivations behind the activities of the Ku Klux Klan, justifying the selection of the option indicating that both statements are true.