What type of stanza is used in this excerpt from edward lear’s “the duck and the kangaroo”?

said the duck to the kangaroo,
"good gracious! how you hop
over the fields, and the water too,
as if you never would stop!
my life is a bore in this nasty pond;
and i long to go out in the world beyond:
i wish i could hop like you,"
said the duck to the kangaroo.

a. couplet
b. quatrain
c. octave
d. sestet