Let n(A) 4 and n(A U B) = 8. (a) What are the possible values of n(B)? (b) If An B=0, what is the only possible value of n(B)? (a) The possible value(s) for n(B) is/are (Use a comma to separate answers as needed. Use ascending order.) (b) The only possible value for n(B), when An B = 0 is