phrases unique to a particular language are called idioms or an idiom
The summarized story that is most likely a myth is option B)
A myth is type of genre in which a story or tale it is believed to be true and in which characters usually have a non human or divine trait.
In this case, the story tells about a mother's sadness and its effect on the growth of crops. According to the myth, the character has the divine power to influence the crops.
I think the answer is C but that’s just a guess