Please solve this game theory question

4. In the Ultimatum Game two players must split 10-units of a resource with each other. One player, the Proposer, gets to propose a splite (e.g. 5-5,7-3,9-1, etc.). The other player, the Responder, decides to accept or reject the offer. If accepted, both players get their share of the proposed split. If rejected, neither players get anything. What are the rational strategies of this game? Defend your answer by providing a short (1-2 paragraphs) supporting argument. Remember to define what you mean by rational