UGC NET Computer Science Q77

Question

The language of the following PDA would be :
$\delta(q_0, a, z_0) = (q_0, aaaz_0)$
$\delta(q_0, a, a) = (q_0, aaaa)$
$\delta(q_0, b, a) = (q_1, \lambda)$
$\delta(q_1, b, a) = (q_1, \lambda)$
$\delta(q_1, \epsilon, z_0) = (q_f, z_0)$, where $q_f$ is a final state.