Which statement best describes internal validity and external validity in exotic rodent research?

• A. Internal validity concerns how well the study is designed and conducted to support causal conclusions; external validity concerns how generalizable the findings are to other populations or settings.
• B. Internal validity is about generalizability to other species; external validity is about the precision of measurements.
• C. Internal validity focuses on ethical approval; external validity focuses on statistical power.
• D. Internal validity only applies to clinical trials; external validity only applies to observational studies.

Answer: (A)