Answer
$\color{blue}{(C \cap D) \cup B = \left\{1, 2, 3, 4, 6, 8\right\}}$
Work Step by Step
RECALL:
(1) $\cup$ represents the union of sets, which is the set that contains the combined elements of the sets involved.
(2) $\cap$ represents the intersection of sets, which is the set that contains the elements common to the sets involved.
Thus,
$C\cap D=\left\{1, 3\right\}$
Combining the elements of the intersection above and the set $B$ gives:
$\color{blue}{(C \cap D) \cup B = \left\{1, 2, 3, 4, 6, 8\right\}}$
