Use reasoning to lead to the answer of the following question:
Sarah thought that buying beer with a fake idea was a good idea. She just wanted to enjoy herself. But it turned to be anything but. What did it turn out to be?\nOptions:\n- a smart decision\n- spend money\n- get arrested\n- stupidity\n- have fun
 Reasoning process:
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One needs to be 21 years or above to buy beer. One's age can be verified using I.D. Faking I.D. is a criminal offense. Committing a crime is stupidity. Stupidity is a type of behaviour. Therefore, the final answer is stupidity.
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