Question

the four most common elements found in living organisms are
o
he
h
p
n
ca
s
fe
c

Explanation:

Carbon (C), hydrogen (H), oxygen (O), and nitrogen (N) are the four most common elements in living organisms as they form the basis of biological molecules like carbohydrates, lipids, proteins, and nucleic - acids.

Answer:

O. Oxygen, H. Hydrogen, N. Nitrogen, C. Carbon