PART A
The word that best describes the overall tone of "O Captain! My Captain!" is Sorrowful.
PART B
The three phrases from lines 17-24 that best support the sorrowful tone are:
- My captain does not answer, his lips are pale and still
- My father does not feel my arm, he has no pulse nor will
- But I with mournful tread,
These phrases convey a sense of loss and mourning, aligning with the sorrowful tone of the poem.