Solution
= Solution
Let $N=|Q|$. The <pumping lemma for regular languages> states that every $w\in L(D)$ with $|w|\geq N$ can be written
$$
w=xyz
$$
with
$$
|xy|\leq N,
\qquad
|y|\geq1,
\qquad
xy^iz\in L(D)\quad\text{for every }i\geq0.
$$
\b[Thus one may take the pumping number to be exactly the number $N$ of states of the given automaton, whether or not all of them are accessible.]