Choose the word that can substitute the given group of words.

Study of body functions

Physiology

The word that can substitute the given group of words "study of body functions" is physiology.

• Genealogy is the study of family history.
• Psychology is the study of the mind and behavior.
• Astrology is the study of the stars and their supposed influence on human affairs.

The word physiology is the most appropriate because it specifically refers to the study of the functions of living organisms, including humans. The other words do not have the same connotation of being the study of how the body works.