Read these lines from walt whitman's "song of myself": the spotted hawk swoops by and accuses me, he complains of my gab and my loitering. i too am not a bit tamed, i too am untranslatable, i sound my barbaric yawp over the roofs of the world. the last scud of day holds back for me, it flings my likeness after the rest and true as any on the shadow'd wilds, it coaxes me to the vapor and the dusk. i depart as air, i shake my white locks at the runaway sun, i effuse my flesh in eddies, and drift it in lacy jags. i bequeath myself to the dirt to grow from the grass i love, if you want me again look for me under your boot-soles. you will hardly know who i am or what i mean, but i shall be good health to you nevertheless, and filter and fibre your blood. failing to fetch me at first keep encouraged, missing me one place search another, i stop somewhere waiting for you. what is one purpose of the imagery in this poem?
a. to make an animal seem like a peer to the speaker
b. to paint a picture of a decaying body in the reader's mind
c. to link two unlike concepts: mountains and burial mounds
d. to put emphasis on the phrase, "i too am untranslatable"

The right answer is the B: To paint a picture of a decaying body in the reader's mind. In this part from that extensive poem, Whitman is describing or illustrating in which ways he is "untranslatable," like the caw of the hawk. By that he means that his self cannot be turned into another being, or into another state. He is ready to disappear - "to depart as air," "to effuse [...] in eddies," to move towards "the vapor and the dusk," and to decompose and grows from the grass he loves. He, nevertheless, will be part of us, of our bodies, of the rapid movement of the clouds... We will be able to find him under our feet. It won't be easy, since he will be unrecognizable as his former self, but we'll be waiting for us, and the echo of his yawp (his powerful words) will remain too, like that of the hawk.      

taking into account that a theme is the central topic a text treats and can be developed through a story, play, poem etc. the following are themes that can be further developed:  

my best friend jeffrey has many unusual interests. (the story could be about each of the unususal interests)

once a man gives his soul over to evil, he can never go back. (this could be a saying or a proverb)

the three sheepdogs lay around the yard all day. (it could be developed detailing how each of these sheepdogs lay around)

a priest's collar has an unusual effect upon people. (it could be developed detailing the different effect upon people)

innocence is a powerful force in a world full of corruption. (it could be developed detailing how is a world full of corruption)

king lear is a play shakespeare wrote later. (it is just a sentence and doesnt give any idea or topic to be discussed in details.

evil often wears the disguise of innocence. (this could be a saying or a proverb)