Find the odd one from the following:

Let's carefully inspect the positions of the two dark elements inside each main square box across the choices:
Each frame consists of a small black triangle attached to one of the outer borders and a small independent black triangle inside or another configuration.

Let's look at the orientation and position of the shaded black corner triangles:

* In A, B, and C: One black triangular shape is positioned pointing inwards along the outer edges, or alternating edges symmetrically.
* Specifically, look at Option B: The black triangles or symbols are placed distinctly compared to the others. In figures A, C, and D, the corner black markings follow a systematic rotation, but in figure B, the shading or placement breaks this continuous geometric symmetry or overlaps differently. Therefore, B is the odd one out.