oxygen, carbon, hydrogen, nitrogen silicon, calcium, oxygen, aluminum carbon, sodium, hydrogen, oxygen sulfur, phosphorous, calcium, nitrogen
I gave my students this multiple choice question: Which four elements make up most of the human body?

Only one answer is correct among these 4 choices:
- oxygen, carbon, hydrogen, nitrogen
- silicon, calcium, oxygen, aluminum
- carbon, sodium, hydrogen, oxygen
- sulfur, phosphorous, calcium, nitrogen

Could you tell me which one is correct?

oxygen, carbon, hydrogen, nitrogen