Which pair includes two survivors of the Spartoi conflicts?

The pair that includes two survivors of the Spartoi conflicts is Echion and Udaeus. The Spartoi were a group of warriors in Greek mythology, specifically mentioned in the context of the founding of Thebes. They sprang from the dragon's teeth that were sown by Cadmus. When the Spartoi fought each other, only five of them survived, and Echion and Udaeus are counted among these survivors.

In the context of the other pairs: Hector and Achilles are notable figures from the Trojan War, not involved with the Spartoi. Perseus and Theseus are heroic figures but do not belong to the Spartan conflict narrative. Likewise, Jason and Atalanta are associated with the quest for the Golden Fleece and Greek epic tales but do not have a direct connection to the Spartoi. This makes Echion and Udaeus the correct choice as they directly relate to the events surrounding the Spartoi myths.