Question

which is one of the six fundamental elements that are found in living organisms?
helium
sodium
oxygen
chlorine

Explanation:

The six fundamental elements in living organisms are carbon (C), hydrogen (H), nitrogen (N), oxygen (O), phosphorus (P), and sulfur (S). Among the given options, oxygen is one of them. Helium is a noble gas and not a fundamental element for life. Sodium and chlorine are important in biological systems (e.g., in nerve impulse transmission and osmoregulation) but are not among the six most fundamental ones that form the basis of biological macromolecules (like carbohydrates, proteins, nucleic acids, and lipids).

Answer:

oxygen