The answer should be D. If the red molecules are oxygen and the compound in NO2, we need the answer to have two red atoms. Also, since the question says there are two NO2 molecules, we need to have an answer with two. Therefore, D is the answer.
Given that blue represent one atom of nitrogen and red represent one atom of oxygen, then one atom of [tex]NO_2[/tex] (nitrogen dioxide) is represented by 2 red spheres bounded to 1 blue sphere. Therefore, two atoms of [tex]NO_2[/tex] are represented by option D.
