A small raised melanocytic nevus is present on the upper labial mucosa. Each of the following changes would be concerning EXCEPT one. Which is the EXCEPTION?

Correct answer: C. Darkens in the sun

• A. INCORRECT. Asymmetry is a warning sign (the A in ABCDE).
• B. INCORRECT. Color variation is a warning sign (the C in ABCDE).
• C. CORRECT. Mild darkening with sun exposure reflects normal melanocyte response and is not by itself a malignant warning sign.
• D. INCORRECT. Irregular or notched borders are a warning sign (the B in ABCDE).