The scenario described indicates that medium brown fur provides an advantage for survival since these mice are less likely to be seen by predators compared to light brown and dark brown mice. This would lead to selection favoring the medium brown fur, which stabilizes the trait around this intermediate phenotype.
Therefore, the correct type of selection is stabilizing, and the distribution curve for the mouse population would look like:
a tall, narrow peak in the center of the graph.
So the answer is:
stabilizing; a tall, narrow peak in the center of the graph.