Answer:
B. hydrogen only.
Step-by-step explanation:
The element hydrogen is a made up of only hydrogen atoms which are the particles in the element.
Hydrogen is an element. It has distinct hydrogen atoms that typifies it.
- Water and carbon is not a hydrogen element. They contain hydrogen, oxygen and carbon.
An element is a distinct substance that is made up of one kind of atom. The only kind of atom in element hydrogen is those hydrogen itself.