The prefix auto means which of the following?

• A. Arm
• B. Self
• C. Life
• D. Eye lid

Answer: (B)

Auto- means self. This prefix signals that the root concept involves the patient or the body's own action. In medical terms you’ll see it in examples like autoimmune (the immune system attacking the body's own tissues) or autonomic (self-regulating, involuntary nerves). So the best answer is “self.” The other options describe unrelated roots: arm would use a different prefix like brachi-; life would use bio- or vita-; eyelid would use palpebr- or blephar-; recognizing auto- helps you quickly decode terms you encounter in the field.