"An increase in nativity feelings in the nation" was the one primary reason among the choices given in the question that revived popularity of the Ku Klux Klan.
An increase in nativist feelings in the nation was the one of the primary reasons for the revived popularity of the Ku Klux Klan.
The Ku Klux Klan generally refered to as the KKK or the Klan, is an American white supremacist hate group which existed in three different eras which had championed extremist reactionary positions such as white nationalism, anti-immigration and Nordicism and anti-Catholicism.
The ideology of the KKK was uncontrolled expression of native feeling.
