In human body percentage of which element is highest?

The correct answer is (D) Oxygen.

• Oxygen is the most abundant element in the human body by mass, accounting for approximately 65% of total body weight. This high percentage is primarily due to the composition of water (H2O), which makes up about 60-70% of the human body, as well as its presence in essential organic compounds like proteins, carbohydrates, and lipids.
• The chemical composition of the human body is essential for physiological processes. Beyond oxygen, other major elements include Carbon (~18%), Hydrogen (~10%), and Nitrogen (~3%). Together, these four elements constitute about 96% of the human body's mass.
• Elimination analysis: Hydrogen is the most abundant element by the number of atoms, but not by mass. Carbon is the foundational element of organic life but ranks second in mass. Nitrogen is vital for amino acids and nucleic acids but constitutes a significantly smaller percentage of total body mass compared to oxygen.