All of these are compounds except oxygen because a compound is two or more different elements bonded together.
I believe its B. <span>The chemical formula for water H2O represents 2 hydrogen and 1 oxygen in the compound. </span>
Because proteins are basically building blocks which mean that they only fit to specific pieces.
This must be your work, otherwise it's against the Brainly code of conduct. If you need help finding a newspaper, go to BBC. They have plenty of relevant articles.