The language accepted by the non-deterministic pushdown automaton
$M=( \{ q_0, q_1, q_2\}, \{a, b\}, \{ a, b, z\}, \delta, q_0, z, \{q_2\})$ with transitions
$\delta (q_0 a, z) = \{ (q_1 a), (q_2 \lambda) \}$;
$\delta (q_1, b, a) = \{ (q_1, b) \}$
$\delta (q_1, b, b) = \{ (q_1 b) \}, \delta (q_1, a, b) = \{ (q_2, \lambda ) \}$ is
- $L(abb*a)$
- $\{a\} U L(abb*a)$
- $L(ab*a)$
- $\{a\} U L(ab*a)$