Could anyone help with these questions

Why might collective bargaining fail, causing a union to go on strike? a the union agrees with the boss about wages. b the boss compromises about work hours. c the factory goes out of business, causing the workers to lose their jobs. d the boss refuses to address dangerous working conditions in the factories.

What problems did socialist thinkers seek to solve

World war 2 was caused, in part, by which of these factors?