It’s the first choice because the C at the end does not pair with anything, it was an extra pair that was made
        
             
        
        
        
It shows the evolution of an being. "Fossil record, history of life as documented by fossils, the remains or imprints of the organisms from earlier geological periods preserved in sedimentary rock." from https://www.britannica.com/science/fossil-record
 
        
             
        
        
        
They only vary only in their "Lipid Groups"
Hope this helped you!:)
        
             
        
        
        
Struggled with this earlier but because of the high altitude only some animals can live there and thrive because of the lower oxygen levels