None of the above.
Sam and Jac are both wrong, but not for the above reasons.
Molecules and compounds are not the same thing. Molecules of compounds have at least two different atoms bonded together, while those of elements have at least two of the same atoms bonded together.
Not all compounds consist of molecules. For example, salt (sodium chloride) consists of sodium ions and chloride ions. An ionic compound does not consist of molecules.
