Answer:
The answer to your question is: The last option
Explanation:
An inert group of atoms that is part of a larger molecule functional group is a part of a molecule that can react, it is not inert, so this option is wrong.
The backbone of a macromolecule, such as a carbohydrate This option is wrong, functional group is not a backbone.
Any molecule that can participate in a chemical reaction This option is wrong because a functional group is not any molecule, is a part of a molecule.
Part of a larger molecule that can react with other atoms or molecules This option is correct this is the right definition of a functional group.
