C- It exhibits cohesive behavior.  Cohesion is when there is mutual attraction between like molecules that makes them to stick together.  
        
                    
             
        
        
        
I think it might be the first one: hiv infections. (hope this helps!)
        
                    
             
        
        
        
The answer is <span>C. reductions of chromosome number.
Meiosis is also known as a reduction division of the cells. The reason for that is because during meiosis the diploid cells are divided into haploid cells. Meiosis consists of two divisions - meiosis I and meiosis II. In meiosis I, the number of chromosomes is reduced, while meiosis II is similar to mitosis. In both meiosis and mitosis, however, cell division, duplication of chromosomes, and production of new cells are common processes.</span>