The prefix Anti- means which?

• A. With
• B. For
• C. Towards
• D. Against

Answer: (D)

In medical terminology, a prefix that signals opposition or counteraction is used to show that the term acts against the base concept. Anti- means against. For example, an antibiotic fights against bacteria, an anti-inflammatory reduces inflammation, and an antidote counteracts a poison. The other options describe ideas like being with, supporting, or moving toward something, which don’t convey opposition. So the best match is anti-, meaning Against.