Which unions merged to form SAG-AFTRA in 2012?

The formation of SAG-AFTRA in 2012 resulted from the merger of the Screen Actors Guild (SAG) and the American Federation of Television and Radio Artists (AFTRA). This merger was significant because both organizations represented different segments of entertainers and performers, and by uniting, they aimed to enhance their bargaining power and better advocate for the rights and interests of their members in the rapidly changing landscape of the entertainment industry. The merger allowed for a more unified approach to issues such as contracts, wages, and working conditions, reflecting the diverse range of media in which members engage.

The other choices reference unions that either do not relate directly to this specific merger or represent different aspects of the entertainment and performing arts landscape. Thus, choice B accurately reflects the key unions involved in this historical consolidation.