Answer
D-Stable
B-Metastable
A and C-Unstable
E-Neutrally stable
Work Step by Step
The stable point is D, for this is the lowest point on the graph. B is metastable, for it is a minimum, but it is not the lowest point. A and C are unstable, for they are maximums on the graph. E is neutrally stable, for it is on a horizontal line.
