Answer :
Hi , the answer is A , because mixtures dont have a fixed composition and they have more than one property so they dont contain only pure substances.
A characteristic of a mixture is it has varying properties.
A mixture is a combination of two or more substances in which they retain their varying properties.
The components or phases of a mixture are mechanically or physically linked. For this reason, its physical properties, such as the boiling or melting point, are often altered.
Mixtures are mixed forms of matter that are extremely common in everyday life, and many of the materials we use are the result of a mixing procedure.
The mixtures are classified according to how feasible it is to identify their different components at a glance:
•Homogeneous mixtures. They are those in which the components cannot be distinguished.
•Heterogeneous mixtures. They are those in which the components can be easily distinguished, because their phases are integrated unevenly and irregularly.
A mixture is a material composed of two or more components joined physically, but not chemically, that is, each component maintains its identity and chemical properties.
Therefore, we can conclude a mixture is the combination of two or more substances in which each of them retains its distinctive properties.
Learn more about characteristic of a mixture here: https://brainly.com/question/24416557