Read the passage from “the caged bird.”
the caged bird sings
with a fearful trill
of things unknown
but longed for still
the stanza best supports a tone of
a)calmness and doubt.
b)secrecy and curiosity.
c)mystery and delight.
d)desire and entrapment.

I believe the best answer for this question would be D, "desire and entrapment." Consider what words the author chooses to describe the bird and its surroundings. "Fearful" is a very telling world; the bird is singing fearfully about things that it dreams about and wishes for. This does not inspire delight or calmness, so you can eliminate two answer options right there. "Things unknown / but longed for still" is also very telling. Longing for something refers to your desire for something. Although the bird cannot attain these things, it still longs for them. Therefore, D is your best answer. Hope this helps.