What defines a mixture? A. can be broken down into its basic substances through physical means B. created through a chemical reaction C. cannot be broken down into simpler substances D. described by a chemical formula

The answer is A. Can be broken down into basic substances through physical means.

Explanation - A mixture is a physical combination of two or more substances blended together without a chemical reaction. Accordingly, each substance found in a mixture keeps its own properties and can be broken down into its basic substances through physical means.