The best anser is C - gaunt. Gaunt means thin and looking exhausted, such as when one is old or tired.
The answer can be actually found directly in the poem, which contains the line: 'An aged thrush, frail, gaunt, and small'. Gaunt is used directly in the poem!
Answer:
The answer would be
<h2>OPTION C !</h2>
That's fit for a concluding sentence !
Answer:
The fickleness of fortune
Explanation: