Which prefix indicates "that which produces"?

The prefix that indicates "that which produces" is correctly identified as "genic." This prefix is derived from the Greek root "genein," which means "to produce" or "to create." In the context of medical terminology, "genic" is often used to describe factors that cause or produce certain effects, conditions, or substances in the body.

For instance, in terms like "carcinogenic," it refers to substances that produce cancer. Thus, the use of "genic" conveys the idea of origin or production in a biological context, making it a fitting choice for this question.

The other options represent different concepts entirely. "Gen" serves as a root and can refer to substances that generate or produce but does not inherently carry the complete meaning of "that which produces" like "genic." "Globin" refers specifically to proteins, often found in hemoglobin, and does not indicate production. "Edema" refers to swelling caused by fluid accumulation, unrelated to production or generation. Therefore, "genic" distinctly communicates the notion of production, justifying its selection as the correct answer.