The correct answer is B. By frequency on the electromagnetic spectrum.
Explanation
Electromagnetic radiation is a set of electromagnetic waves generated by sources of the electromagnetic field that propagate at the speed of light. Many of the phenomena that are evidenced daily are related to electromagnetic radiation, for example, light, heat, radio waves, and television, among others. These types of radiation are differentiated from each other through different ranges of frequencies or wavelengths. In the same way, the frequency serves to classify the different types of waves. Based on the above, the correct answer is B. By frequency on the electromagnetic spectrum.