Labor unions are groups of workerks that join together in order to protect workers' rights.
During the Second Industrial Revolution (between 1850-1870 until 1914) the work conditions were terrible taking work schedules of up to 14 hours under dangeroues conditions with minimum pay.
The goverment took little interest in protecting workers' rights, and if an employee complained he/she was replaced. Becasue of this many workers began to revolt and created unions to get fair wages, less hours and safe conditions.
The correct answer is the third one: Laissez-faire policy caused poor working conditions in factories.
