A is the correct answer !!!
Not necessarily, object A could also be neutral, and becoming a dipole due to object B's charge. A charged object can induce a dipole in a neutral object, and that object would then become attracted without being charged.
The correct answer is Destructive Interference.Consider the image attached below. Two waves are travelling towards each other. Blue wave always has a positive peak and the red wave always has a negative peak.
Now imagine these waves are moving through a rope. If blue waves will try to move the rope in positive direction, the red wave will pull it down, and thus the two waves will cancel the effect of each other. Thus resulting in a destructive interference.