Answer: Option (A) is the correct answer.
Step-by-step explanation:
It is known that an element contains same type of atoms and it cannot be broken down into simpler substances.
For example, gold is an element which contains only atoms of gold.
A molecule is defined as the substance which contains same type of elements in fixed ratio by mass.
For example,
is a molecule.
Whereas a compound is defined as the substance which contains different type of elements that are chemically combined together in a fixed ratio by mass.
For example,
is a compound.
Thus, we can conclude that one gram of pure gold would contain lots of gold atoms.