Let's try to orient ourselves. First off, from looking at the 4 options, you should be able to tell that the perpendicular leg of the trapezoid is closer toward us, and the longer angled side goes away from us. From this you should be able to say that, because of this orientation and the way the trapezoids lie, the top side that you see has to be the shaded one, eliminating options A and B. C and D both have the short vertical shaded side. The difference is the large rectangular face. Should it be shaded or not? From the pattern, the shaded one should be the one that lays on the visible side.
The difference between A and D is another one of those trick folds. A can only be possible (having the unshaded trapezoid sitting in that orientation) if the pattern is folded out of the page. This cannot be the case. The pattern has to be folded in, which leads to the shaded trapezoid sitting in that position.
