Which prefix denotes an association with swelling?

The prefix that denotes an association with swelling is "edema-." In medical terminology, "edema" refers to the accumulation of fluid in the tissues, which leads to swelling. This term is derived from the Greek word "oidema," meaning swelling or puffiness. Therefore, when a medical condition includes "edema," it directly indicates that swelling is a significant characteristic of that condition, highlighting its relevance in clinical settings.

While the other options represent different concepts, they do not pertain to swelling. "Megal-" relates to enlargement or large size, "auto-" denotes self or automatic processes, and "carcin-" is associated with cancer. Each of these prefixes has its distinct meaning and application in medical terminology, making "edema-" the correct choice for depicting swelling.