The correct answer is A) Knights of Labor
The labor union that was open to workers from any trade was the Knights of Labor.
The Knights of Labor was the labor Union that was opened to workers from any trade. In opposition to the American Federation of Labor that only accepted limited membership to very good craftspeople and it focused on economic reforms, the Knights of Labor -the first one formed- was open to receive any kind of worker. It had its peak moments in 1880 with the work of labor leaders such as Joseph Bath and Terence V. Powderly.
