Which of the following is an example of ionizing radiation?

Ionizing radiation refers to radiation that carries sufficient energy to displace electrons from atoms or molecules, creating ions in the process. Among the options provided, gamma rays are a category of electromagnetic radiation that possesses high energy and the ability to penetrate most materials, which qualifies them as ionizing radiation. Gamma rays are produced in radioactive decay and are utilized in various applications, including medical diagnostics and treatments, largely because of their ionizing properties.

In contrast, microwaves, electromagnetic radiation (which encompasses a broad spectrum of wavelengths, including non-ionizing forms of radiation), and lasers do not carry enough energy to ionize atoms or molecules. Therefore, gamma rays stand out as the correct example of ionizing radiation due to their specific energy levels and ionization capabilities.