WAEC Mathematics 2002 Question 4

Given that P = {b, d, e, f} and Q = {a, c, f, g} are subsets of the universal set U = {a, b, c, d, e, f, g}. Find P'∩Q.

1. A.{a, c}
2. B.{a, c, d, g}
3. C.{c, d, g}
4. D.{a, c, g}