Answer
$A' = \left\{b, c, d, i, j, k\right\}$
Work Step by Step
RECALL:
$A'$ represents the complement of set $A$. The complement of a set is the set that contains all the elements of the universal set $U$ that are not in set A.
Notice that the elements of the universal set that are not in $A$ are $c, d, j, k, b,$ and $i$.
Thus,
$A' = \left\{b, c, d, i, j, k\right\}$