Maybe you should ask some real English questions .-.
        
             
        
        
        
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!
        
             
        
        
        
C..............................
        
             
        
        
        
False when you love someone you will make mistakes a relationship isn't perfect you always say sorry even if you're in a relationship