Match the Research with the Researcher(s)

Match the research with the researcher(s) .
-Bärbel Inhelder

A) a study of the lineage of the Kallikak family
B) an analysis of the childhood biographies of eminent historical geniuses,which led to the argument that had intelligence tests been given at the time these intellectually prominent figures would have achieved high IQ scores as children
C) the first serious studies of the preoperational stage of development
D) the study of adult intelligence and the creation of an intelligence test for adults