The correct answer is B) Mixture.
Explanation:
Atoms are the basic units of elements, and they combine to form molecules and compounds.
A Mixture is formed when two or more substances (elements or compounds) are combined without undergoing a chemical reaction. In a mixture, the components retain their individual properties and can usually be separated by physical means.
A Molecule is formed when two or more atoms chemically bond together.
A Compound is a substance formed when two or more different elements chemically react and bond together in fixed proportions.
In a mixture, there is no chemical bonding between the substances involved, which is the key distinction between a mixture and a compound.