The correct answer is D. Carbon.
Buckminster fullerene is a spherical allotrope of carbon with the formula C60. It is a cage-like molecule with 60 carbon atoms arranged in a truncated icosahedron, resembling a soccer ball. Fullerenes were first discovered in 1985 by Harold Kroto, Robert Curl, and Richard Smalley, for which they were awarded the Nobel Prize in Chemistry in 1996.
Fullerenes have a wide range of potential applications, including in materials science, electronics, and medicine. They are also being studied as possible fuels for spacecraft.
The other options are incorrect because they are not elements that can form fullerenes. Boron is a metalloid, iron is a metal, and phosphorus is a nonmetal.