There are two particular cases, the first is when Object A is attracted to the neutral wall. This would indicate that the object is not neutral, as there is an attraction.
At the same time we know that Object A is attracted to an object B. And therefore, the load of A must be opposite to that of B. Remember that opposite charges attract each other. If the charge of object B is positive, then the charge of object A will be negative.
Option B is correct: It has a negative charge.
I do believe that the answer is D.
Hope this is right! Have a great day! :-)
Answer:
Rate of change of area will be 
Explanation:
We have given rate of change of radius 
Radius of the circular plate r = 52 cm
Area is given by 
So 
Puting the value of r and 

So rate of change of area will be 
Gravity if I’m not mistaken
If you put a penny in each light spot the penny that the light is shining on will recive the most energy.