Question

based on this virtual experiment, which substances proved to contain proteins?
○ milk and potatoes
○ egg whites, water, and the unknown
○ egg whites, potatoes, and the unknown
○ milk, egg whites, and the unknown

Explanation:

Milk and egg - whites are well - known protein sources. Potatoes are mainly a source of carbohydrates, and water does not contain proteins. Without further information about the "unknown" substance, assuming common knowledge about known substances, milk and egg - whites are proteins.

Answer:

D. milk, egg whites, and the unknown