A shoplifter and a security guard are playing a simultaneous game. If the shoplifter steals and the security guard is vigilant, the shoplifter gets caught she suffers a loss of 20, and the security guard gets a bonus worth 15. If the shoplifter steals and the security guard is not vigilant, she does not get caught and gains 15 and the guard loses 5. If the shoplifter does not steal and the guard is vigilant, the guard loses 3 for the effort, while the shoplifter gains nothing and if the shoplifter does not steal and the guard is not vigilant, neither gain anything If the security guard is somehow certain that the shoplifter would not steal, his best response would be