What lincoln meant when he said: "a house divided against itself cannot endure, permanently half slave and half free. i do not expect the union to be dissolved--i do not expect the house to fall--but i do expect it will cease to be divided. it will become all one thing, or all the other."

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.