The alarm stage<span>, the resistance </span>stage<span>, and the exhaustion </span>stage<span>. ... The changes that occur in the alarm </span>stage<span> prepare ypu to either "fight" the stressor or "take flight" and escape. Thus, this inital </span>reaction<span> of the</span>body<span> to </span>stress<span> is called the fight-or-flight </span>response<span>.</span>
        
             
        
        
        
Explanation:
option B and option D (might be ) but B is confirmed 
 
        
             
        
        
        
Answer:
Stabilizing selection
Explanation:
This occurs when selective pressures occur against the two extremes of a trait (wasps prey on larvae inside the smallest galls; birds prey on larvae inside the biggest galls). As a result, this would select for larvae in medium sized galls, while the number of larvae in small and large galls decreases. 
 
        
             
        
        
        
Answer:
I believe that the smallest is Nucleotide, bases, genes, DNA, Chromsomes. 
Explanation:
 
        
             
        
        
        
Answer:
B. Temperature
Explanation:
The heart rate depends on the temperature so the heart rate is dependant and the one that changes is independant