Which two elements make up the most common compound in the human body

The two elements that make up the most common compound in the human body are oxygen (O) at 65% and carbon (C) at 18%. I hope this helped :)

Almost 99% of the mass of the human body is made up of six elements: OXYGEN,CARBON,hydrogen,NITROGEN,calcium, and phosphorus. Only about 0.85% is composed of another 5 elements: potassium, sulfur, sodium, chlorine, and magnesium. Really hoped this helped.

The answer would be d. pili