The fourth vertex needed to create a rectangle with the given vertices must be the point that completes the rectangle by forming a right angle with the point (-5, -7).
The distance between (-17, -7) and (-5, -7) is 12 units, so the fourth vertex must be located 12 units above (-17, 15) on the y-axis.
Therefore, the fourth vertex is O(-17, 27).
None of the given options match this point, so none of them are correct.