Answer: The correct answer is Glucose.
The chemical formula of the given molecules are-
Carbon dioxide is CO₂, which means that it contains 2 oxygen and 1 carbon atom and therefore 3 atoms per molecule.
Glucose- C₆H₁₂O₆, which means that it contains 6 carbon, 12 hydrogen, and 6 oxygen atoms. Thus, total atoms are 24 per molecule.
Oxygen- O₂, which means that it contains 2 atoms of oxygen.
Water- H₂O, which means that it contains 2 hydrogen and 1 oxygen atom and therefore 3 atoms per molecule.
Thus, glucose has greatest number of atoms per molecule.