Donatello's David is significant for many reasons. For one, not since antiquity was there a free standing n.ude statue of a man.David also exhibits the humanist thought of the early renaissance because the beauty of the human form is captured in this statue. 
        
             
        
        
        
E
F sharp
D
G sharp
B
A
E
C sharp
        
             
        
        
        
The Parting of Lot and Abraham is about their literal parting - Abraham took his family to Canaan, as God wanted him to, whereas Lot went to Sodom, and defied God's wishes. Now, having this in mind, maybe this mosaic does symbolize B. heaven, as Abraham and his family would go to heaven eventually, because they obeyed God's orders and wishes.