Final answer:
A ring around the sun is known as a solar halo, and the bright images on either side are called sundogs, occurring when sunlight is refracted by ice crystals in cirrostratus clouds.
Step-by-step explanation:
A solar halo, also known as a 22-degree halo, is an atmospheric phenomenon that occurs when sunlight passes through ice crystals in cirrostratus clouds, creating a circle around the Sun. Accompanying this ring, there can be two bright spots known as sundogs, which appear due to the same refraction of sunlight. The term 'sundog' is also known by its scientific name, parhelion, and these bright spots occur at approximately 22 degrees on either side of the Sun, often as part of the halo effect.
The correct answer to the student's question is A) Sundog.