Answer
$\text{True}$
Work Step by Step
$\text{The elements of set D are }$1, 2,$ and $3\\$.
$\text{The elements of set B are }$ $2, 4, 6,$ and $8$.
$\text{Some elements of set D}$ ($1$ and $3$) $\text{are not in set B.}$
$\text{Thus, set D is not a subset of B.}$
$\text{Thus, the given statement is TRUE.}$
