The correct answer is option 2: Gamma rays. Gamma rays are a type of electromagnetic radiation that carry the highest amount of energy among the options listed. These rays have the shortest wavelength and highest frequency in the electromagnetic spectrum.

UV rays (option 1) are also a form of electromagnetic radiation, but they have lower energy compared to gamma rays. UV rays have longer wavelengths and lower frequencies than gamma rays.

X-rays (option 3) are also a type of electromagnetic radiation, but they have lower energy compared to gamma rays. X-rays have shorter wavelengths and higher frequencies than UV rays.

Infrared (IR) rays (option 4), also known as heat radiation, have the lowest energy among the options listed. IR rays have longer wavelengths and lower frequencies compared to all the other options.

Therefore, gamma rays carry the maximum energy among the listed radiations. They are commonly used in medicine for cancer treatment and sterilization processes due to their high energy levels.