Final answer:
B. Molecular crystals
The solid formed when oxygen freezes at very low temperatures is best described as molecular crystals, which are composed of individual molecules held together by weak intermolecular forces.
Step-by-step explanation:
The best term to describe the solid formed when oxygen freezes at very low temperatures is molecular crystals.
Molecular crystals are solids that are composed of individual molecules held together by weak intermolecular forces, such as van der Waals forces. Oxygen (O2) is a diatomic molecule, and when it freezes, the individual oxygen molecules arrange themselves in a regular, repeating pattern to form a crystalline solid.
Other examples of molecular crystals include ice (solid water), solid carbon dioxide (dry ice), and many organic compounds.