What types of light does sunlight include that reaches the Earth's surface?

Sunlight at the Earth's surface is composed of various types of electromagnetic radiation, which includes UVA, UVB, visible light, and infrared light. UVA and UVB are two types of ultraviolet radiation that can have significant effects on human skin, including tanning and the risk of skin damage. Visible light is the part of the spectrum that the human eye can see, enabling perception of colors and brightness. Infrared light contributes to the warmth we feel from sunlight but is not visible.

The inclusion of all these components in the correct choice reflects the comprehensive nature of sunlight as it interacts with Earth's atmosphere and surface. The other options either exclude important components of sunlight or incorrectly include types of radiation that do not reach the Earth's surface in significant amounts, such as X-rays and gamma rays, or focus too narrowly on just the ultraviolet spectrum. Understanding this composition is essential for both safety in tanning and in appreciating how sunlight influences our environment.