Which of the following best states the relationship that Olmsted and Riis had to the study

Which of the following best states the relationship that Olmsted and Riis had to the study of sociology？

A．Their goals were supported by the research conducted later by sociologists.

B．Their approach led them to oppose empirical sociological studies.

C．They had difficulty establishing that their work was as important as sociological research.

D．They used evidence from sociological research to urge national leaders to invest in urban development.

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