Final answer:
Norse mythology stories were predominantly collected in the Prose Edda, written by Snorri Sturluson in the 13th century, which is a crucial source for understanding Norse culture and beliefs.
Step-by-step explanation:
The stories of Norse mythology were most notably collected in the Prose Edda. The Prose Edda, also known as the Younger Edda, is a compilation of Norse myths and epic tales that form the basis of the Norse pagan religion. It was written by the Icelandic poet and historian Snorri Sturluson in the 13th century. The Prose Edda provides a detailed narrative of the creation of the world according to Norse belief, the adventures of the gods, and the prophesied end of the world, known as Ragnarök. It's an essential source for understanding the ancient Norse culture and belief systems. The other options given, such as the Valkyrie Chronicle, Epic of Gilgamesh, and Song of the South, are either not related to Norse mythology or are different cultural epics altogether.