The question is as following:
Which substance has the greatest contribution to the anabolism of glucose in plants. A- Oxygen (O2). B- Water (H2O). C- carbon dioxide (CO2).
The official answer given in this question was C, however I believe H2O and CO2 are equally important in their contribution, because glucose consists of 6 carbon atoms and 12 hydrogen atoms which respectively come from the 6 water molecules and the 6 carbon dioxide molecules needed for the light reaction and calvin cycle. Which step am I missing to the answer? This was by the way a high school biology national olympiad question in my home country, nl.
Kind regards, I'm looking forward to your response!