...the fact that they are a physical contaminant. 
        
                    
             
        
        
        
1. Protects human health and environmental safety 
2.sets and monitors food packaging and labeling
3. Regulates policies for agriculture and forestry
        
             
        
        
        
Answer: Incentive 
Explanation: 
Mitchell feels full after having food and is not willing to eat but his anticipation to eat chocolates is his incentive as he is full.
The incentive is a force of motivation which motivates the person to achieve the goal of interest. Even if the tasks is complete the person will do more work in order to get incentive.
Here, the chocolate bar is acting as an incentive in which the person is willing to eat chocolates even if he is full.