Answer:
C. rollback 
Explanation:
The retina of the eye is located inside the eye making it impossible for the retina to roll back. Only the eye itself can rollback. 
 
        
             
        
        
        
Answer:
Explanation:
It is a concern to managers in an organization because it is important for the organization to get the number and quality of staffs needed to attain the goals and objectives of the organization.
Selection and recruitment is also important in order to ensure the continuity of the company , it will also fulfills the organisations job requirements and also this provide a pool of employees in which the management will have to choose the right or best candidates for the job position.
 
        
             
        
        
        
Force = mass*acceleration so 
3.6*2.5 =9 Newtons
        
             
        
        
        
My Answer: They contain a high diversity of organisms.
Hope I helped! :D