Final answer:
The National Recovery Administration (NRA) sought to protect workers by promoting worker unions and establishing codes of fair practice. This agency faced difficulties in creating and enforcing codes for various industries.
Step-by-step explanation:
The NRA, or National Recovery Administration, sought to protect workers by promoting worker unions and establishing codes of fair practice that included minimum wages and maximum work hours. These codes ensured workers' rights to organize and use collective bargaining to ensure fair wages and working conditions. However, the NRA faced difficulties, such as the challenge of creating and enforcing codes for numerous industries, including those with less relevance to workers' rights.