Which prefix is associated with the meaning "against"?

The prefix "anti-" is used to indicate opposition or resistance to something. In medical terminology, it commonly appears in terms like "antibiotic," which refers to a substance that works against bacteria, or "antibody," which is a protein produced by the immune system to neutralize foreign objects like bacteria and viruses. Understanding this prefix helps in comprehending various terms in healthcare that describe treatments or responses that counteract a specific disease or condition. The prefix's clear denotation of opposition is what makes it the correct choice in this context.