What is indicated by the suffix -logy?

The suffix -logy is derived from the Greek word "logos," which means "study" or "discourse." In medical terminology, -logy is used to indicate a field of study or a branch of knowledge. For example, "biology" refers to the study of life, and "psychology" is the study of the mind and behavior. This suffix helps to classify and define various scientific disciplines by highlighting their focus of study. Thus, the correct answer identifies -logy as representing the concept of study, making it a fundamental suffix in medical and scientific terminology.