The correct answer is: D. None of these
A ridge is the line where two sloping surfaces of a roof meet at the top. A hip is the line where two sloping surfaces of a roof meet at an angle other than a right angle. A valley is the line where two sloping surfaces of a roof meet at a lower point than the ridge.
In the case of a roof with an external angle exceeding 180°, the line of intersection of the surfaces of the roof would not be a ridge, hip, or valley. It would be a complex line that would be difficult to describe using any of these terms.