The correct answer is: D) Gluon.
The particle that carries the strong force is the gluon.
The strong force is one of the four fundamental forces in nature, responsible for holding atomic nuclei together. It is the force that binds quarks, which are elementary particles, together to form protons and neutrons. The exchange of gluons between quarks mediates this strong force.
The other answer options listed are not associated with the strong force:
A) Graviton: The graviton is a hypothetical particle that is associated with the gravitational force, not the strong force.
B) W boson: The W boson is a particle that mediates the weak nuclear force, which is responsible for certain types of radioactive decay.
C) Z boson: The Z boson is another particle that mediates the weak nuclear force, similar to the W boson.
D) Photon: The photon is a particle that carries the electromagnetic force, responsible for interactions between charged particles.
Therefore, the correct answer is: D) Gluon.