​Which of the following characteristics uniquely defines the anthropological approach?

A) ​a concern with the study of humans
B) ​a focus on human relationships and society
C) ​a focus on humans as biological organisms
D) ​a holistic perspective

A holistic perspective is a defining characteristic of the anthropological approach, as it involves studying humans in their entirety, including their cultural, social, economic, and biological aspects. The other choices are important aspects of anthropology, but they are not unique to the field. Other disciplines, such as sociology and biology, also focus on human relationships and society and humans as biological organisms, respectively.