The answer is b) Surveying opinions of fellow classmates
        
             
        
        
        
Answer: Lysosome
Explanation:
The lysosome is an organelle found in cells of eukaryotes.
Its functions include:
I) It contains several hydrolytic enzymes such as 
- glycosidases that break down complex sugars (polysaccharides), 
- proteases that break down proteins,
- and sulfatases that hydrolyze sulphur-containing compounds, 
- other enzymes for lipids and Nucleic acids
II) it also digest worn out organelles, and engulfed viruses and bacteria.
III) and helps to remove wastes from the cell.
 
        
             
        
        
        
Environmental scientists are using GPS ( It is effective but expensive) aerial monitoring (Quick but not the easiest), RFID tags, (mostly for long-term monitoring) and hidden cameras are used to study polar bear behavior without interruption to their environment.
        
             
        
        
        
The answer to this question is c! Thanks for posting your questions!