B. plastic packing
A and D are biological hazards and C is a chemical hazard
        
                    
             
        
        
        
Explanation:
The liver is connected to two large blood vessels, the hepatic artery and the portal vein. The hepatic artery carries blood from the aorta to the liver, whereas the portal vein carries blood containing the digested nutrients from the entire gastrointestinal tract, and also from the spleen and pancreas to the liver.
 
        
                    
             
        
        
        
Answer:
The correct option is : d. Syncytia
Explanation:
Syncytia are the multinucleated cells formed from multiple fusions of the uninuclear cells.
During a infection, an infected cell fuse together with the neighboring host cells, leading to the formation of large multinucleated cells, called syncytia.
Viruses like herpesviruses, induce the formation of multinucleated syncytia cells. 
 
        
             
        
        
        
"RESPIRATION" causes the amount of carbon dioxide in the air to increase
Hope this helps!