Answer:
This type of story is an example of a creation myth. (letter C)
Step-by-step explanation:
Creation myths are stories found in different cultures all over the world. Those stories explain how the world was created as well as many natural phenomena such as rain, lightning, the sunrise and sunset, etc.
Commonly, such stories will include gods or god-like animals and beings who, whether intentionally or not, end up originating the world as we know it. In some stories, humans beings already exist, and they even interfere or help in the creation. With that in mind, we can easily see that the story described in the question is an example of a creation myth. It has the elements mentioned above - a god, sky children (god-like beings), and the building of the world.