Solution (source code)

= Solution

A word $w$ is accepted by the <Epsilon-NFA> precisely when
$$
\widehat\delta_E(q_0,w)\cap F_E\ne\varnothing.
$$
By part (b), this reached subset is exactly $\widehat\delta_D(q_D,w)$, and by the definition of $F_D$ the intersection condition is equivalent to $\widehat\delta_D(q_D,w)\in F_D$. Hence
$$
\boxed{\mathcal L(D)=\mathcal L(E).}
$$