Use the relation to answer the questions below. Read the questions carefully and be sure to answer all parts completely. Relation: {(1, 2), (3, 5), (2, 7), (3, 6), (5, 8)} Part A (2 pts): What is the domain of the relation? Provide your answer using proper set notation. Part B (3 pts): Is the relation a function? Explain how you know it is or is not a function.