Answer:
C. The population of mice would decrease. 
Explanation:
 
        
             
        
        
        
None of them.
I'm assuming that you left off an option. a prokaryotic cell is a single-celled organism, generally a bacteria. an example would be e-coli. 
        
                    
             
        
        
        
Pleiotropy occurs when one gene influences multiple, seemingly unrelated phenotypic traits. A single gene is responsible for pigmentation and hearing.