What reason did the National Labor Relations Act give for allowing labor unions to form?

ALabor unions make conditions safer in workplaces.
BThe flow of commerce cannot continue without collective bargaining.
CCollective bargaining ensures equality and protects the flow of business.
DExperience proves that workers are interrupted if collective bargaining exists.

One of the rights that The National Labor Relations Act (1935) guarantees is the employee's right to self-organization, to form, join, to assist labor organizations and to bargain collectively

According to Section 1 "Findings and Policies" of the Act, the right to collective bargaining ensures equality and protects the flow of business.

When employers deny the employees their right to organize and bargain collectively, it can lead to strikes, unrest or other forms of industrial conflict or interruption, which stops the efficiency and efficacy of the business, that is to say, it stops its flow.

The practice of collective bargaining also ensures equality by giving workers full freedom of association and self-organization to negotiate the terms and conditions of their employment (such as wages and hours) or other mutual aid or protection.