Physics Help

first mass of all objects are not same.  use force = mass * acceleration.

Yeah so basically, your graph is a function that relates force (y-axis) and acceleration (x-axis). If we use Newton's Second Law: F = m*a, we get that the slope of all this functions is not other than the mass of the object we're analyzing. We also know that force is the range of the function, i.e. we will see how it behaves given the acceleration. Because we're interested on how large the mass is, we have to see how steep the slope is. 

The result would be the following: F > C > A > D > B > E. 
This also proves that not all the masses are the same. There is a greater force given the same acceleration because the masses are different.