CHNOPS stands for Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur.

• A. CHNOPS stands for Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur
• B. CHNOPS stands for Calcium, Hydrogen, Neon, Oxygen, Phosphorus, Sulfur
• C. CHNOPS stands for Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Silicon
• D. CHNOPS stands for Carbon, Helium, Nitrogen, Oxygen, Phosphorus, Sulfur

Answer: (A)

CHNOPS are the six elements most commonly found in living organisms and they form the building blocks of key biomolecules. Carbon provides the versatile backbone of organic molecules; hydrogen and oxygen are abundant in water and in most organic compounds; nitrogen is essential for amino acids and nucleotides; phosphorus is a critical component of ATP, nucleic acids, and phospholipids; sulfur appears in certain amino acids and vitamins. The option that lists these six elements matches this set exactly. Other choices introduce elements not part of this standard group, like calcium, neon, silicon, or helium, so they don’t fit CHNOPS.