According to Norse Mythology, Ragnarök is a series of future events that means great disasters for the world and the end of many important and powerful gods:

In Norse mythology, Ragnarök is a series of future events, including a great battle foretold to ultimately result in the death of a number of major figures (including the gods Odin, Thor, Týr, Freyr, Heimdallr, and Loki), the occurrence of various natural disasters, and the subsequent submersion of the world in water. Afterward, the world will resurface anew and fertile, the surviving and returning gods will meet, and the world will be repopulated by two human survivors . Ragnarök is an important event in the Norse canon, and has been the subject of scholarly discourse and theory. source: Wikipedia article on Ragnarök

After Ragnarök, it is said that the world will be repopulated with two human survivors. How will these two human survivors be chosen? Will they be randomly chosen or selected by the remaining gods who didn't die during Ragnarök?