Answer: Option (B) is the correct answer.
Explanation:
Anything that has space and occupies volume is known as matter.
A pure substance can be molecule of an element or molecule of a compound.
A molecule can have atoms of either same or different element. Whereas a compound has atoms of different elements.
For example, [tex]H_{2}[/tex] is a molecule with similar atoms, that is, hydrogen element.
[tex]H_{2}O[/tex] is a compound that contains hydrogen and oxygen atom.
Thus, we can conclude that pure substance contains molecule of an element or molecule of a compound.