Other Than the Great Transformation's Challenges to the Racial State

Other than the Great Transformation's challenges to the racial state, what other historical event do Omi and Winant suggest also challenged the racial state before the 1960s?

A) The American Industrial Revolution
B) The election of Barack Obama as President of the U.S.A.
C) The Great Depression and World War II
D) The American Civil War and Reconstruction Era .
E) 9/11 and the War on Terror