Why did Socialist parties grow during the period of labor unrest and high unemployment of the 1920s and 1930s?

If you are on USA Test Prep, the answer is B) Socialist parties tried to work with the labor unions in forming a political alliance.

Socialist parties grew during the period of labor unrest and high unemployment because their platform appealed to people that were experiencing inequality and widespread misery which they blamed on the government and corporations. The promise of socialism and its ideologies readily appealed to them as a result of their misery