Mesons are found in A. Laser beam B. X-rays C. Gamma rays D. Cosmic rays

The correct answer is D. Cosmic rays.

Mesons are unstable subatomic particles that decay into other particles within a very short period of time. They are found in cosmic rays, which are high-energy particles that come from outside the solar system. Cosmic rays are made up of protons, neutrons, and electrons, as well as mesons.

Laser beams are made up of photons, which are particles of light. X-rays are a type of electromagnetic radiation with a wavelength shorter than visible light. Gamma rays are a type of electromagnetic radiation with a wavelength shorter than X-rays.

Mesons are not found in laser beams, X-rays, or gamma rays.