In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").
Q: Fact1: Skin color is another polygenic trait., Fact2: Phenotypic expression of polygenic traits varies over a wide range., Question: Phenotypic what of skin color varies over a wide range (A) humans (B) percents (C) drastically (D) lizards (E) the environment (F) expression (G) percentages (H) calibrated
A:
F