Answer:
protein 
Most genes contain the information needed to make functional molecules called proteins. (A few genes produce regulatory molecules that help the cell assemble proteins.) The journey from gene to protein is complex and tightly controlled within each cell.
 
        
                    
             
        
        
        
The correct answer is: D.  damage to nerves that control the stomach.
The vagus nerve is a cranial nerve that controls stomach contractions and thus, the movement of the food. When the vagus nerve is damaged, the muscles of the stomach do not function properly, so gastroparesis occur. Consequently,  food then moves slowly or even totally stops moving through the digestive tract.
 
        
                    
             
        
        
        
Theory I believe Hope it helps
        
             
        
        
        
Along with neuropsychological assessment, brain imaging and recording techniques may be used to shed light on relationships between brain function and underlying abnormalities.
Brain imaging is technique used to image the structure (tumor or injury) and function (metabolic diseases and lesions) of the central nervous system.