Using function images, there is no way to draw them now. Draw y=│logaX│ own function image. Its image is the image of function y=logaX, and the transformation is as follows: the upper part of X is motionless, and the lower part is folded on the X axis. Its image characteristics are: first time and then decline, and the lowest point is (1, 0).

There are two function values equal to 1: (1/a, 1)(a, 1). In the title, the value range is (0, 1). Then, the domain should include at least one of two intervals (1/a, 1) or (1, a). And a> 1; Therefore, 1- 1/a is less than a-1; Therefore, the minimum length interval is (1/a, 1). So 1- 1/a=5/6. We can get a=6.

Answer b, over

If the minimum length interval is mistaken for (1, a), then you have chosen the wrong C.

Finally, I need to explain: I personally think that "if the minimum length of interval [m, n] is 5/6" in the title should be changed to "if the minimum length of interval [m, n] is 5/6".