Which allotropes of carbon form geodesic globes?

Answer: Option A

* Allotropes are different structural forms of the same element.
* Carbon is special because it can form many different allotropes.

* Fullerenes: These are spherical or ellipsoidal molecules made of carbon atoms arranged in a geodesic structure, like a soccer ball. Think of them as tiny cages!

* Carbon nanotubes: These are cylindrical structures made of rolled-up sheets of graphite. They aren't spherical, so they don't form geodesic globes.

* Diamond: This has a giant covalent network structure, making it very hard. It doesn't form geodesic globes.

* Graphite: This consists of layers of carbon atoms arranged in hexagonal sheets. These sheets are flat, and do not form geodesic globes.

Therefore, only fullerenes form geodesic globes.