Which of the following is NOT a duty of citizens in a state?

Spying on the state is NOT a duty of citizens. In fact, espionage (spying) against one's own country is a criminal offence that can amount to treason. A citizen who spies on the state by passing classified information to foreign governments or hostile entities undermines national security and sovereignty.

The recognised duties of citizens in a state include:

• Prevention of crimes - citizens have a civic duty to assist in maintaining law and order, report criminal activity, and cooperate with law enforcement agencies.
• Voting at elections - participating in the democratic process by voting is a fundamental civic duty that ensures legitimate governance.
• Payment of taxes - citizens are obligated to pay taxes to fund public services, infrastructure, and government operations.

Other standard duties of citizens include loyalty to the state, respect for the national flag and anthem, obedience to the laws of the land, readiness to defend the country when called upon, and respect for the rights and dignity of fellow citizens. All of these strengthen the state, whereas spying against the state actively works to undermine it.