You need to provide a picture
The answer is a meteor.
Meteors make flashing light when they enter the Earth's atmosphere. This is actually meteors on fire, because our atmosphere makes them burn when they come in contact, and crashes them under the pressure. This makes up for a beautiful sight on the night sky, and people often refer to the burning meteors as ''falling stars'', and make wishes as well.
C, details that help readers visualize the settings better. A wouldn't work because it doesn't help the setting, B doesn't help the setting either and D would only add more confusion so UT would have to be C by process of elimination.
