Concept:A course of action logically follows only if it is a practical, moderate step directly related to the issue stated.
Explanation:The statement says that nuclear power cannot make a country secure.
So, increasing nuclear capability (I) is not directly rejected as harmful, but stopping it is not a necessary outcome of the statement alone.
Destroying nuclear capability (II) is an extreme action and does not logically follow from the statement.
Since nuclear power is not the real source of security, the country should improve other means of security, such as diplomatic relations (III).
Therefore, only course of action III follows.
Answer:Option C: Only III follows.