Answer:
Option D 
+2
Explanation:
We know that Calcium has 20 electrons and 20 protons. It lost two electrons, it has 20 protons, but only 18 electrons. This makes calcium a positive ion with a charge of +2.
 
        
             
        
        
        
If the group of all forces acting on an object is balanced, 
then the effect of all of them is the same as if there were 
no forces at all on the object.  In that case, the object 
continues moving in a straight line at a constant speed.
        
             
        
        
        
You can tell because the line bends and the closer it is to horizontal or past horizontal it is more dense