OOOh
, so it is w.r.t weight/weight stoichiometric comparison. I thought that they asked for the abundance w.r.t the number of atoms or molecules.
I think that I read it somewhere in my matric's chemistry textbook that they have different relevant measures which include weight/weight, volume/weight,volume/volume and weight/volume etc.
The reasons for this inference is already mentioned by me in my earlier posts to the topic. But as u have found the evidence, i think Oxygen is an acceptable answer as the most weighty element in human body.
Thank You