Which of the following most effectively addressed the concerns that Upton Sinclair and others had for industrial workers?
President Theodore Roosevelt's promise for a "Square Deal"
State legislation that limited the hours and working conditions for women and children
Legislation passed during the Wilson presidency to legalize the organization of labor unions
The formation of the Socialist Party under the leadership of Eugene Debs

Legislation passed during the Wilson presidency to legalize the organization of labor unions .

Explanation:

The Anti-trust Act is a section of enactment enacted by the U.S. Congress in 1914. The act represents unfair business methods, such as monopolies and price-fixing, and sustains several rights of labor. Aside from preventing the methods of price differentiation and anti-competitive organizations, The bill established the House with an amazing majority in 1914. President Woodrow Wilson approved it into law.

your answer would be (b)