The Ku Klux Klan virtually collapsed in the late 1920s when
a. the immigration restriction laws of the early 1920s were repealed.
b. the organization was publicly exposed as a corrupt and cynical racket.
c. the advent of radio led to a new level of public knowledge and tolerance.
d. the Klan proved unable to implement its program.
e. both political parties sharply criticized the Klan as un-American.