The answer is C, because if something contagious we’re to threaten the population of the species then not having any variant means they’re all the same and it would kill them all and cause them to go extinct
        
             
        
        
        
The answer is true..............
        
                    
             
        
        
        
Answer:
Genes.
Explanation:
Genes are present on DNA that are inherited from parents to their offspring. Genes may be defined as the segment of DNA that ultimately form a particular protein product. 
The particular trait of an organism is determined by the specific combination of the inherited genes. The genes are nearly same in all the human beings and there mutation can cause observable phenotype traits.
Thus, the correct answer is option (2).