In Venn diagrams, the complement of a set includes all elements not in the set. Make sure to carefully identify the region that is shaded or marked in the diagram.
In the given Venn diagram, the shaded area represents the region outside of both sets \( A \) and \( B \), which corresponds to the complement of the union of \( A \) and \( B \). In set notation, this is written as:
\[
A' \cap B' \quad \text{(the region outside both \( A \) and \( B \))}
\]
Thus, the correct answer is \( A' \cap B' \), which represents the region that is outside both sets \( A \) and \( B \).