Study of mankind

Answer: Option D

One word substitute is Anthropology.

Pathology: the science of the causes and effects of diseases, especially the branch of medicine that deals with the laboratory examination of samples of body tissue for diagnostic or forensic purposes.
Physiology: the branch of biology that deals with the normal functions of living organisms and their parts.
Philology: the branch of knowledge that deals with the structure, historical development, and relationships of a language or languages.
Anthropology: the study of human biological and physiological characteristics and their evolution.