A traditional story that explains a belief system, a natural phenomenon, or a world view of a group of people is called a.
ANSWER: Myth
I believe the answer is B.
Let's look at it with punctuation: My father, an expert in the field of astronomy, recently discovered a comet.
After reading it makes more sense to have the pauses. Hopefully that helps.
A primary source is a direct account from someone who experienced an event or person. A secondary source is an indirect account from someone who has acquired information from other sources in order to tell about an event or person. I don't know what book you are referring to, but I hope this helps!