Answer:
The answer is D. All of these
Explanation:
Both mixtures and compounds have to be made of two or more substances. In a mixture, those are two or more pure substances. In a compound, it would be two or more atoms combined. A mixture is not combined chemically - you can separate the parts using physical means (like size in filtration or boiling point in distillation). A compound is combined with bonds. The bonds can't be broken without using chemical means. So all three options are correct.
