Which of the following statements about gamma rays is true?

Gamma rays consist of high photons which do not have a mass but a charge equal to that of an electron.

Gamma rays consist of low-energy photons of high wavelength.

Gamma rays consist of high-energy photons with a high penetration power.

Gamma rays are short bursts of very high-energy electrons.

Gamma rays consist of high-energy photons with a low penetration power.