Which suffix means treatment in medical terminology?

• A. ology
• B. ectomy
• C. therapy
• D. itis

Answer: (C)

The main idea is that the suffix -therapy denotes treatment. In medical terms, attaching -therapy to a root signals a method or modality used to treat a condition, such as chemotherapy (treatment with drugs), physical therapy, or psychotherapy. This is what makes it the right choice: it directly conveys the concept of treatment. The other suffixes signal different ideas—-ology means the study or science of something, -ectomy indicates surgical removal, and -itis means inflammation—so they describe fields of study, procedures, or a disease state, not the act of treating.