The correct answer is the second one “an absence of love or passion.” In the poem, the general intention of the author is to describe his feelings about the love/passion that it is leaving his life. The sentence “dead leaves and snow”, is the way in which he introduces the absence feeling that he is going through. The birds, as well as the leaves of the tree, are metaphors of love, which are abandoning the tree (his life). 
 
        
                    
             
        
        
        
It's A. subordinate because it begins with a subordinate conjunction "because" and its adverbial clause since it asks the question "why?"
        
             
        
        
        
A.First persons point of view is told from perspective