A. Immune system 
It helps our bodies fight everything that comes in our path.
        
                    
             
        
        
        
Answer:
a. more widespread in the body and affect distant targets.
Explanation:
Hormones are released into the blood by the dustless endocrine glands and the circulating blood delivers hormones to cells throughout the body. Therefore, hormones affect the distantly located cells throughout the body. For instance, growth hormone released by pituitary gland affects soft and hard tissues throughout the body.  
On the other hand, the nervous system release neurotransmitters that affect the postsynaptic neuron or the muscle or gland cells present close to the site of their release. Target cells of neurotransmitters are more limited and include muscle (smooth, cardiac, and skeletal) cells, gland cells, and other neurons only.  
 
        
             
        
        
        
The answer to this is passive hyperemia.
        
             
        
        
        
The tiny solid particles which play in the cloud formation are solvents.