Turn sadly to a adjective first: sad
Add most or -est
So it can be most sad or saddest
        
             
        
        
        
C. They feared the radicals who had taken power in France during the revolution
        
             
        
        
        
The symbolic meaning of gold in the poem is best described by option C. The wonderful things in life that do not last. 
In the poem, gold is used to describe the transition of nature from one state to another. Everything that is colored gold does not last long, that is why it is said that nothing gold can stay. Here, we get the idea that we should get the most of these valuable "things" before they are no longer there.
 
        
             
        
        
        
6 would be the second one
7 would be the last one
8 would be the third one 
9 would say the second one