The answer is: D
Explanation
The correct option is D: Public Policy.
This is because public policy is not one of the grounds on which reasonable restrictions on the right to freedom of speech and expression can be imposed, according to Article 19 (2) of the Indian Constitution.
The other options are valid grounds for imposing such restrictions, as they are related to the sovereignty and integrity of India, the security of the state, friendly relations with foreign states, public order, decency or morality, contempt of court, defamation, or incitement to an offence.
Public policy, on the other hand, is a vague and subjective term that can vary from time to time and place to place, and thus cannot be a valid basis for restricting the fundamental right of freedom of speech and expression.