Explanation:

- Option 1: Rousseau

- Jean-Jacques Rousseau argued in his work "Discourse on the Origin and Basis of Inequality Among Men" that social inequality began with the concept of private property. He famously noted that the first person who fenced in a piece of land and called it his own was the founder of civil society and inequality.

- Option 2: Marx

- Karl Marx discussed inequality in terms of class and capitalism, focusing on exploitation and ownership of the means of production. However, he came after Rousseau and expanded on property-related ideas.

- Option 3: Parsons

- Talcott Parsons was a sociologist known for structural functionalism. He explained inequality through roles and contributions in society, not through the original emergence of property.

- Option 4: Mills

- C. Wright Mills critiqued power structures and elites in society but did not focus on the original emergence of inequality via property.