Explanation:

- Option 1: Spencer – Herbert Spencer was an early sociologist who talked about society like an organism, but he did not formally introduce the term “social structure.”

- Option 2: Durkheim – Émile Durkheim was a major figure in sociology and discussed social facts and collective conscience, but he did not coin the term.

- Option 3: Radcliffe Brown – He was the first to systematically use and develop the concept of “social structure” in anthropology and sociology. He defined social structure as an arrangement of persons in relationships defined by rules and norms.

- Option 4: Ginsberg – Leonard Ginsberg contributed to sociology, but not specifically to the origin of the concept of social structure.

Correct Answer: Option 3: Radcliffe Brown