Draw two rays with a 45-degree angle, and let a circle with a radius of 2 move on the horizontal axis. When there are several intersections between the circle and another ray, there are several solutions.

Then you will find that these two solutions really didn't appear until the circle moved a distance of 2.

Until the circle is at 2* root number 2, the circle no longer intersects with another ray.

So the answer should be C.