According to the given picture, the 3-D that can be made from this is a square pyramid. We know this, because a square pyramid has a squared base and 4 triangular faces.
We also can discard a triangular prism because it has 2 triangular bases and 3 rectangular lateral faces; and a rectangular prism because it has 2 rectangular bases and 4 rectangular lateral faces.
In conclusion, the correct answer is C. square pyramid.