There's been a lot of bad news for polar bears recently. In 2007, for example, scientists reported that if global warming continues unabated, the population could drop two-thirds by 2050.
 
        
             
        
        
        
<span>more prey than predators</span>
        
             
        
        
        
Answer:
d. anaerobic 
Explanation
anaerobic means no oxygen and fermentation occurs when there is a lack of oxygen