Read the passage from “the caged bird.”
the free bird thinks of another breeze
and the trade winds soft through the sighing trees
and the fat worms waiting on a dawn bright lawn
and he names the sky his own.
which additional line best matches the tone of the stanza?
and he thunders through the stormy sky
and he drifts among the cottony clouds
and he charges past the sorrowing sky
and he flies right through circular clouds

As it is discussed in the question, this given line is additional which is not included in the poem. Since it is a multiple choice question, we have to work through the answers. It is easy to observe that first and third options does not follow the regular rhyme of the poem since the stanza contains rhyme. We choose second option over the last one because the second one obeys the rule of prosody, as well. So that, the correct answer is the 2nd one.

in our power to make a world happy - to teach mankind the art of being so - to a character hitherto unknown - and to have, as it were, a new creation intrusted to our hands, are honors that command reflection, and can neither be too highly estimated,