This one is a toughie. I am usually pretty good with PAT. I broke this down into 2 parts. Firstly, I imagined how this object would fold and you can see it the flaps fold over the hypotenuse of the triangle. Then, I visualized matching up each corner of the sample with the choices. So For choice A, take the shaded sides you know are shaded and match it up. You can see that the shaded side opposite to the double shaded sides should be visible so strike out that choice. For choice B, the same problem occurs but with respect to the double shaded side. For choice C, one of the shaded sides is one the wrong face. So by process of elimination, the answer is choice D from what I can tell. Hope that helps. The key is folding it first and try placing the corners of the model on the corners of the choices and rotating it until you find one that works. You probably know this already but make sure you are folding the model in the right direction. Thanks again for the practice
if you have time, i suggest you actually draw it on a piece of paper with proper shading, cut out the shape, and fold it yourself. then u can examine it from every angle and figure out a strategy from there. this helped me because in my kaplan book, there are several patterns they let you cut out and fold yourself for practice.