Which combining form means skin?

• A. Bi/o
• B. Dermat/o
• C. Erg/o
• D. Lys/o

Answer: (B)

The main idea is recognizing the root that refers to the skin. Dermat/o comes from the Greek derma meaning skin, and it functions as a combining form used to build terms about the skin. That’s why it’s the right choice: it directly denotes skin, and you can see it in words like dermatitis (inflammation of the skin), dermatologist (skin doctor), and dermatology (the study of the skin).

Bi/o means life (as in biology), erg/o relates to work or energy, and lys/o means to dissolve or break down. Those roots point to other concepts, not skin, which is why they don’t fit the question.