
The correct answer is A. vary.
Explanation:
"Vary" means to differ or change from one instance to another, which fits the context of features like height, weight, and skin color differing from person to person.
"Change" (B) and "alter" (C) imply a more specific kind of transformation, which isn't as fitting in this context as "vary," which simply denotes differences.
"Convert" (D) typically refers to a change in form or state, often in a more complete or specific manner, which doesn’t apply well here.
So, the sentence would read:
"Features such as height, weight, and skin color vary from individual to individual and from face to face."