What Does the Possibility of Terrorism, Such as a Nuclear

What does the possibility of terrorism, such as a nuclear attack or release of a deadly virus allow the government to do?

A) It allows the justification of state activity that would be illegitimate in normal circumstances.
B) Governments normally respond to a terrorist threat of any kind by declaring martial law.
C) In the case of a deadly virus, governments are allowed to pour huge amounts of money into curing diseases currently thought.
D) Politicians are free to use it to scare citizens into voting for them, and they always use this tactic to win.