Which of the following best expresses the main idea of the selection
A．Both the social group theory and the scientific research methods developed by Durkheim have contributed much to the field of sociology.
B．Durkheim believed that individual members of a group strongly influence the group' s ways of thinking, feeling, and behaving.
C．The research study conducted by Durkheim provided strong evidence that suicide rates vary among members of different social groups.
D．Through his research, Durkheim made great strides in distinguishing sociology from psychology.