The National War Labor Board was created during World War I and then reestablished during World War II. Its main purpose was to prevent work stoppages and strikes by mediating labor disputes between workers and management in industries related to war production.
Therefore, the National War Labor Board was largely in charge of mediating labor disputes and preventing work stoppages and strikes in industries related to war production, rather than dealing with issues related to discrimination in hiring practices or affirmative action policies.
Hence, the correct answer is none of the options.