Ultraviolet radiations from sunlight cause a reaction producing

The correct option is carbon monoxide.

Ultraviolet (UV) radiation from sunlight is a highly energetic form of electromagnetic radiation. When these high-energy UV rays penetrate the Earth's atmosphere, they interact with various carbon-containing organic compounds present in the air, water, and soil.

Through a process known as photochemical degradation or photo-oxidation, UV light provides the energy required to break down complex carbon-containing molecules (such as dissolved organic matter in aquatic environments or volatile organic compounds in the atmosphere). This chemical breakdown under the influence of solar UV radiation directly leads to the formation and release of carbon monoxide (CO).