Answer: Option A.
The hypothalamus is the brain structure responsiblre for regulating thirst, hunger, temperature and sexual behaviour.
Explanation:
Hypothalamus is a part of brain structures located at the floor of the third ventricle below the thalamus and its control the autonomic system.
It controls hunger, thirst, temperature, fatigue, sleep and sexual behaviour . Hypothalamus secretes the anti diuretic hormones which increases the level of water absorbed into the blood by the kidneys and corticotropin releasing hormone which regulate immune system.
 
        
             
        
        
        
Your answer would be C: Arachnids
        
             
        
        
        
In the winter its color changes to more resemble their <em>winter</em> surroundings, so they are more white, enabling them to blend in better with their white surroundings. In summer, its color changes to more resemble its <u><em /></u><em>summer</em> surroundings, so they are more brown like the rocks and ground around them.
        
             
        
        
        
I pick c. because I really can't see the screen very well.
        
                    
             
        
        
        
Explanation:
Whereas primary tissues allow for vertical growth, secondary tissues allow for lateral growth: they allow stems and roots to become wider. In roots, the formation of both secondary meristems involves the pericycle.