Dr. Frederick McKay's investigation of the Colorado Brown Stain represents which core public health function?

Correct answer: A. Assessment

• A. ✅ Correct. Assessment is one of the three core functions of public health (Assessment, Policy Development, Assurance). McKay's investigation — identifying the cause (high natural fluoride) and the effects of Colorado Brown Stain — is a classic example of the assessment function.
• B. ❌ Surveillance is a component of assessment, not the overall function.
• C. ❌ Assurance involves ensuring necessary services are provided — comes after identification.
• D. ❌ Policy development follows assessment when evidence is translated into guidelines.