Let U = (1, 2, 3, 4, 5, 6, 7, 8), A = (3, 5, 6), B = (1, 5, 7, 8), and C = (1, 2, 4). Consider the following. AUB What does AU B' mean? O the union of sets A and B the intersection of sets A and B O the intersection of set A and the complement of set B the union of set A and the complement of set B O the complement of the union of sets A and B Find the following sets. (Use the roster method to write the set. Enter EMPTY or a for the empty set.) A- B- Use the sets above to find A U B. (Use the roster method to write the set. Enter EMPTY or for the empty set.) AUB-