B
Explanation:
Since mirrors reflect things, when you shine light at a mirror, it will bounce off of the mirror, or reflect, and shine the opposite direction of where the original light is pointed. The answer would be B because light doesn't go through the mirror, or run along it.
Think of when you through a basketball on the ground. If you bounce it at an angle, it won't just come back to you in the same angle. It will keep bouncing at the same angle you through it. This is pretty much what describes the relationship between ray A and ray B.
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