Options: (i) density. (ii) cigarettes. (iii) Earth orbiting the Sun. (iv) gravity. (v) thyroid hormones. (vi) force. (vii) Climate change. (viii) Temperature changing.
Given those answer options, answer the question: Fact 1: Thyroid hormones increase the rate of metabolism in cells throughout the body. Fact 2: Everyone has a different metabolism. Given the two facts above, what effects everyone differently?
A:
(v)