President Truman on March 21，1947 issued an executive order，initiating a comprehensive investigation of all federal employees.This was the beginning of _______.

President Truman on March 21，1947 issued an executive order，initiating a comprehensive investigation of all federal employees.This was the beginning of _______.

A.McCarthyism

B.persecution of federal employees

C.widespread persecution of Communists and progressive people

D.clearing out Soviet spies

正确答案是C