Your answer would possibly be D. Yes because he is trying to provide the best possible care to his patient.
if this is incorrect, then i am sorry.
        
                    
             
        
        
        
Shelters should be accessible to all animals, have sufficient ventilation, and be  of the Guide to discuss the housing requirements of all species used in research. If they are housed individually or exceed the weights in the table, animals. Loafing areas, exercise lots, and pastures are suitable for large farm animals.
Hope this help have a great day :)
 
        
             
        
        
        
Answer:
Eating a healthy diet.
Explanation:
Skin contains different chemicals that helps to defense us from the pathogens. Skin consists of collagen, fats, keratin and proteins. Skin acts as the first line of defense in the organisms.
The collagen and keratin protein in skin are linked together by the cross- linking between them. The increase in these cross linking decrease the flexibility of the skin. This cross linking can be reduced by eating a more healthy diet rich in vitamins, minerals and carbohydrates.
Thus, the answer is eating a healthy diet.