What Ushered in a More Cautious Era of Labor Organizing

Multiple Choice

What ushered in a more cautious era of labor organizing after 1955?

A) company owners being able to maintain control over management decisions after settlement of the 1946 strikes
B) the requirement of union officers to sign affidavits certifying they were not members of the Communist Party
C) the abolishment of the closed shop that required all workers to be in a union
D) the merger of the Congress of Industrial Organizations with the American Federation of Labor