C- 10ft. Hope this helped. Have a great day! :D
        
                    
             
        
        
        
To calculate the ideal mechanical advantage for an inclined plane, divide th length of the incline by the height of the incline. 
Therefore; IMA = L/h
L= 3.0 m, while h =1.0 m
 IMA = 3/1
         = 3
Therefore the IMA of the ramp is 3 
This means the ramp increases the force that is being exerted by 3 times.
        
             
        
        
        
C is true, and just one of those has as much mass as about 1,840 electrons.