Choose the word which is different from the rest.

The answer is C. Astrology.

Nephrology is the study of the kidneys. Entomology is the study of insects. Mycology is the study of fungi. Pathology is the study of disease. Astrology is the study of the stars and planets and their supposed influence on human affairs.

Astrology is different from the other words because it is not a science. The other words are all sciences that study real things in the world. Astrology, on the other hand, is a pseudoscience that claims to predict the future based on the positions of the stars and planets. There is no scientific evidence to support the claims of astrology.