Answer:
The components of a pure substance are single elements or compounds instead of a mixture of compounds
Step-by-step explanation:
This is the most nearly correct answer. The mixture could also consist of different elements or of elements and compounds.
A and B are wrong. The components of a pure substance are mixed evenly and do not have particles in suspension.
C is wrong. The statement is true, but it does not explain the difference between pure substances and mixtures.