Most of the concentration of which gas results from the activity of producer organisms?
A B C D
nitrogen oxygen water vapor carbon dioxide
Question: Most of the concentration of which gas results from the activity of producer organisms?
(A) nitrogen
(B) oxygen
(C) water vapor
(D) carbon dioxide

Answer: (B) oxygen
Answer: (C) water vapor
Question: Most of the concentration of which gas results from the activity of producer organisms?
(A) nitrogen
(B) oxygen
(C) water vapor
(D) carbon dioxide
Answer: (B) oxygen