What is this supposed to be
The answer is <span>C. I worked from dawn until dusk.</span>
This sentence use a time reference to convey a serious tone. The time reference from dawn until dusk has the meaning that the speakers has been working really really hard recently and to the point of sacrificing other aspects of the speaker's life.
The correct answer should be “it is not always stated overtly and is understood only by reading the whole poem”.
this is correct because the theme usually does not change itself, but there can be multiple themes analyzed. it is rarely stated overly and requires some analysis and understanding so as to find it.