What systems are causing inequality and how are they doing it

It is said that Capitalism is the system that causes inequality.

Capitalism embodies and sustains an Enlightenment agenda of freedom and equality. Typically there is freedom to trade and equality under the law, meaning that most adults (rich or poor) are formally subject to the same legal rules. But with its inequalities of power and wealth, capitalism nurtures economic inequality alongside equality under the law. Using the data from twenty-three developed countries and from the separate states of the United States, they observed negative correlations between inequality, on the one hand, and physical health, mental health, education, child well being , social mobility, trust and community life, on the other hand. They also found positive correlations between inequality and drug abuse, imprisonment, obesity, violence, and teenage pregnancies. They suggested that inequality creates adverse outcomes through  psycho-social stresses generated through interactions in an unequal society.

answer; i believe the correct answer is (4) flip a coin as each participant arrives,heads indicates assignment to the first group: tails indicates assignment to the second group;