In this task, we ask you to write an implausible answer to a question that involves event "frequency", which refers to how often an event is likely to be repeated. For example, "taking showers" typically occurs ~5 times a week, "going to Saturday market" usually happens every few weeks/months, etc. Even though there exist multiple wrong answers, we only need a single wrong answer. Please try to keep your "answer" as simple as possible. Concise and simple "answer" is preferred over those complex and verbose ones.

Let me give you an example: Sentence: Jack played basketball after school, after which he was very tired. 
Question: How often does Jack play basketball?
The answer to this example can be: twice an hour.
Here is why: "Playing basketball" normally occurs few times a week. Playing "twice an hour" is unlikely.

OK. solve this:
Sentence: The Vice President's task force was just getting under way when the 9/11 attack occurred. 
Question: How often do such terrorist attacks happen in the world?
Answer:
once every 5 years.