#### Answer

false

#### Work Step by Step

$B'$ is the set that contains the elements of the universal set $U$ that are not elements of $B$.
Since $B=\left\{1, 3, 5\right\}$, then $\color{blue}{B' = \left\{2, 4, 6, 7, 8\right\}}$.
Thus, the given statement is false.