Answer:
A) Adaptations
Explanation:
If a species learns to adapt to their environment, then they will not become extinct
 
        
                    
             
        
        
        
Growing willow for biofuel is sustainable development because it is a source of fuel which potentially will never run out. For every willow tree that is cut down, another can be planted in its place. This means that the source of fuel is potentially limitless and subsequently sustainable. 
        
             
        
        
        
46 Cromosomas
Las células del ser humano tienen 23 pares de cromosomas, 22 pares de autosomas y un par de cromosomas sexuales. Por tanto, cada individuo tiene 46 cromosomas en sus células. Por lo tanto, el número de cromosomas presentes en una célula nerviosa de un ser humano es de 46 cromosomas.
        
             
        
        
        
The roots of the trees keeps the soil in place 
        
             
        
        
        
Are there choices to choose from, because that is a very general question?