Read the first four lines and the final six lines of Keats's "Ode to a Nightingale."
My heart aches, and a drowsy numbness pains
My sense, as though of hemlock I had drunk,
Or emptied some dull opiate to the drains
One minute past, and Lethe-wards had sunk:
. . .

Adieu! adieu! thy plaintive anthem fades
Past the near meadows, over the still stream,
Up the hill side; and now ’tis buried deep
In the next valley-glades:
Was it a vision, or a waking dream?
Fled is that music:−Do I wake or sleep?

Question:
Read the passage from Keats's "Ode to a Nightingale" to answer this question.
The first four lines include:
Question 15 options:

end rhyme.

simile.

allusion.

All of the above

None of the above