941 - Logical Reasoning

Question : A weapons-smuggling incident recently took place in country Y. We all know that Y is a closed society. So Y's government must have known about the weapons.
Which of the following is an assumption that would make the conclusion above logically correct?

1. If a government knows about a particular weapons-smuggling incident, it must have intended to use the weapons for its own purposes.
2. If a government claims that it knew nothing about a particular weapons-smuggling incident, it must have known everything about it.
3. If a government does not permit weapons to enter a country, it is a closed society.
4. If a country is a closed society, its government has a large contingent of armed guards patrolling its borders.
5. If a country is a closed society, its government has knowledge about everything that occurs in the country.