In the empirical approach, the relationship studied is typically between exposure and response.

• A. risk-benefit
• B. causation-reaction
• C. cause-effect
• D. exposure-response

Answer: (D)

In the empirical approach, you focus on what the data show about how a measured exposure relates to an observed outcome. This is all about how varying levels of exposure correspond to changes in the response, often captured as an exposure–response curve. That direct link between dose or exposure and effect is what the term exposure-response conveys, and it fits the idea of analyzing real-world observations to quantify how the outcome moves as exposure changes.

The other ideas don’t describe this direct data-driven relationship as clearly. Risk-benefit speaks to weighing overall harms against benefits rather than a specific exposure-to-outcome pattern. Causation or cause–effect implies proving a mechanism, which goes beyond the descriptive empirical relationship. And a nonstandard phrase like causation-reaction isn’t the typical way to describe the studied link.