For photoelectric absorption to occur, the gamma energy must be:

Photoelectric absorption is a process where a photon (in this case, gamma radiation) interacts with an atom and transfers all of its energy to an inner-shell electron, resulting in the ejection of that electron from the atom. For this interaction to occur effectively, the energy of the incoming gamma photon must meet certain criteria related to the electron's binding energy within the atom.

The correct response indicates that the gamma energy must be equal to the electron binding energy or slightly larger. This is because the photon needs enough energy to overcome the attractive forces that hold the electron in the atom (the binding energy). If the photon's energy is exactly equal to the binding energy, it has just enough energy to eject the electron. If the photon has slightly more energy than the binding energy, the excess energy is transformed into kinetic energy of the ejected electron. This is essential for the photoelectric effect to take place, as it specifically requires the complete transfer of energy from the photon to the electron.

Other options suggest that the photon energy could be less than or arbitrarily larger than the binding energy, which does not correctly represent the energy relationship necessary for photoelectric absorption. Having less energy cannot release the electron, as the photon would not have the capacity to overcome the binding