The passage below is an excerpt from Robert Owen's A New View of Society (1813-1816). Use the passage to answer the following question:

Train any population rationally, and they will be rational. Furnish honest and useful employments to those so trained, and such employments they will greatly prefer to dishonest or injurious occupations. It is beyond all calculation the interest of every government to provide that training and that employment; and to provide both is easily practicable. --Public Domain

Which theory, described in this passage, was challenged by Karl Marx?

Mercantilism
Classical liberalism
Communism
Utopian socialism