Between 1947 and 1951, What Did the Loyalty Boards That

Between 1947 and 1951, what did the loyalty boards that were established to root out subversives in government service do?

A) They uncovered evidence of massive subversion and espionage within the Departments of State and Defense.
B) They restricted their investigations to potential subversives in high-risk areas of government service.
C) They forced several thousand government employees to resign and led to the dismissal of almost six hundred on charges of disloyalty.
D) They restored to federal government employees a sense of calm and confidence that had been missing since the end of World War II.
E) They were declared unconstitutional by the Supreme Court.