Final answer:
UVA radiation (A) is present all year and is more prevalent than UVB, as it has a longer wavelength and consistently penetrates the Earth's atmosphere. Option A is correct.
Step-by-step explanation:
The type of radiation that is present all year and more prevalent than UVB is UVA radiation (A). This question pertains to the spectrum of electromagnetic radiation emitted by the sun.
Electromagnetic radiation includes radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays, all of which have different wavelengths and energy levels. Ultraviolet light from the sun consists primarily of UVA and UVB rays, where UVA has a longer wavelength and penetrates the Earth's atmosphere more consistently throughout the year.
It is important to understand the electromagnetic spectrum sequence, which typically follows the order from longer wavelengths and lower energy to shorter wavelengths and higher energy: radio, microwave, infrared, visible, ultraviolet, X-ray, and gamma radiation.
UVA falls just below UVB in terms of energy and is significantly more prevalent. X-rays and gamma rays have much shorter wavelengths and higher energy than ultraviolet light, thus can penetrate objects more successfully, but they are not as prevalent in the environment as UVA.