hi there
your answer to this is :   C) vessel elements
EXPLATION:
The most distinctive xylem cells are the long treachery elements that transport water. Tracheids and vessel elements are distinguished by their shape; vessel elements are shorter, and are connected together into long tubes that are called vessels. Xylem also contains two other cell types: parenchyma and fibers.
i hope this helped you out 
have a great afternoon
FaithRawlins14
 
        
             
        
        
        
Organic matter in soil is also called humus.
        
                    
             
        
        
        
Answer:
Essential to the formation of all known life, evidence of stable liquid water elsewhere could indicate an environment beyond Earth that could sustain the formation of extraterrestrial life
Explanation:
If there is water on other plants, Mars for example, then that shows there may be a sign of living life or a opportunity for us.
 
        
             
        
        
        
Answer:
Both the nature of the gene and its environment can influence the mutation rate. 
Explanation:
Mutations are caused by environmental factors known as mutagens. 
Types of mutagens include 
- radiation, 
- chemicals, and 
- infectious agents.
 
        
                    
             
        
        
        
Answer:
The third option is correct.
Hope this helps.