Why Is It Advantageous to Employers to Have a Large

Why is it advantageous to employers to have a large number of marginal people (uneducated and/or undocumented) in the work force?

A) Because desperate people will work for very low wages, thus depressing wages for all workers
B) To have someone to blame for industrial accidents
C) To have someone to blame for unionization efforts, thus depressing interest in unions among more educated workers
D) Because employers want the opportunity to improve society by raising people out of poverty