Taking the set of natural numbers as the universal set,write down the complements of the following sets:
$A = \{ x : x \text{ is a perfect cube} \}$

• A
  $A' = \{ x : x \in N \text{ and } x \text{ is not a perfect cube} \}$
• B
  $A' = \{ x : x \in N \text{ and } x \text{ is a perfect square} \}$
• C
  $A' = \{ x : x \in N \text{ and } x \text{ is an even number} \}$
• D
  $A' = \{ x : x \in N \text{ and } x \text{ is an odd number} \}$