Final answer:
The sunlight that reaches Earth is mostly converted into infrared radiation upon striking the surface. The electromagnetic spectrum includes various types of radiation, and infrared has longer wavelengths than visible light. Ultraviolet light, with shorter wavelengths, is energetic and can damage living tissues.
Step-by-step explanation:
Shortwave sunlight passes through Earth's atmosphere, where it strikes the surface and is converted into longer-wavelength infrared radiation. The correct answer to the question is a) Infrared. When sunlight, which includes a range of electromagnetic radiation types, contacts Earth's surface, much of it is absorbed and re-emitted as infrared radiation, which has a longer wavelength than the visible light initially received.
The electromagnetic spectrum includes various types of light such as radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays, which all possess differing wavelengths and energy levels. Ultraviolet (UV) light, for instance, is particularly potent in terms of energy because it has shorter wavelengths than visible light. This property is why UV light can be harmful to living tissues, as it can break down biomolecules such as DNA.