Which prefix meaning 'negative, none' is represented by 'an-'?

• A. A-
• B. Endo-
• C. An-
• D. Caud/o

Answer: (C)

An- is the negative prefix that means without or lacking. It shows up in medical terms to indicate the absence of something, so you’re dealing with a concept of not having what the root describes. For example, anemia means without enough blood, and anaerobic means living without oxygen, while anhydrous means without water. This form of the prefix is used before roots that start with a vowel, which is why you see an- here. The other options point to different ideas: endo- means inside, and caud/o refers to the tail, neither of which convey negation.