Professor Dumbledore Studies Concordance Rates as They Affect Schizophrenia

Professor Dumbledore studies concordance rates as they affect schizophrenia.This means that he studies ____.

A) the likelihood that adopted children share more in common with their biological parents than with their adoptive parents
B) the likelihood that adopted children share more in common with their adoptive parents than with their biological parents
C) the likelihood that both twins of a twin pair will show the same characteristics
D) the occurrence of specific diseases in the general population