Question

changing the color of a surface, such as the ______ on a tree in autumn, requires a change in chemical makeup. source: science magazine drifts crystals gems leaves

Explanation:

We need to find the word that fits the context of a tree's surface whose color changes in autumn. "Drifts" are related to movement (like snow drifts), "crystals" and "gems" are not parts of a tree's surface that change color in autumn. "Leaves" are the parts of a tree that change color (due to chemical changes in chlorophyll and other pigments) in autumn.

Answer:

D. leaves