What caused workers to unite and create labor unions?

a.) purchasing factories from the owners.

b.) to keep workers safe from unsanitary, corrupt, and dangerous working conditions.

c.)to eliminate health insurance provided by the employer.

d.) to go back to cheaper primitive production methods.

B. To help keep workers safe from unsanitary, corrupt, and dangerous working conditions.

Explanation:

Workers began to protest and denounce what they perceived as the unsanitary, corrupt and dangerous working conditions. That was the beginning of the labor movement.

Unions enhanced workers' ability to strike and demand concessions from the employers. Paid leave, social security, minimum wages, insurance (medical insurance in most European countries) ... those were some of the things the labor movement (boosted by unions) achieved around the world.

the real answer is b

the answer is mass marketing.