D. this is the correct answer because the question is showing a comparison of sizes rather than the actual sizes which eliminates B. A and C have no relevance.
<span>This would be the atomic mass. In an atom of carbon-12, there are 6 protons and 6 neutrons at rest (electrons have a negligible mass and are usually not part of the overall mass calculation). All atomic masses are based off the measurements of this specific iteration of carbon.</span>
The molecule that contains the fewest number of Hydrogen atoms would be B. Al(OH)3. It only has 3 Hydrogen atoms.
