4. if n is the set of natural numbers that are factors of 20, choose the selection below that correctly shows this set in roster form. {2, 4, 5, 10} {2, 4, 6, 8, 10, 12, 14, 16, 18, 20} {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20} {1, 2, 4, 5, 10, 20} 5. suppose u = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} is the universal set, and p = {1, 4, 9}. what is ? {2, 3, 5, 6, 7, 8} {2, 4, 6, 8} {1, 2, 3, 4, 5, 6, 7, 8, 9, 10} {2, 3, 5, 6, 7, 8, 10}