单项选择题

A store exposure to crime does not diminish when the store is closed. On the contrary, as night falls, criminals are on the move looking for the best crime opportunity. This period of time is, in fact, critical. Owners generally rely only on the presence of physical barriers and electronic security. But they do not seem to be able to stop a determined effort by a group of professional criminals.
When closes, commercial stores can be attacked in many different ways such as:
Three-minute burglary. It involves attacking a glass front door or a window at night, smashing a display case, and stealing merchandise left out of safes. This type of criminals has little concern about the alarm system: They intend to be gone before any reaction is made to the alarm signal. In the United States, this type of burglary represents nearly 75% of all the burglary events n the jewelry industry.
Ramming. It means driving into a store by smashing the front windows or doors. It has also been a practice used by criminals to gain access to valuable merchandise.
Safecracking. It involves attacking a safe and stealing its contents. It should not be left out as a risk for store owners, but it makes up for a very small percentage of closed store crimes. This type of crime is decreasing as a result of the high security safes and alarm systems.
Robbery is not frequent during closing time, but always represents a threat to store owners. Criminals may in fact decide to take them (or family members) hostage when at home and force them back to the store.
To reduce the risks for a closed store crime to occur, the following reduction strategies are recommended:
Safes. Time locks on safes, which allow- opening only at specified times, can be considered as an added source of protection. Making use of different safes for high value merchandise can also reduce potentially heavy losses.
Exterior and interior lighting. This is essential, as it remains one of the most effective weapons against burglary, theft and armed robbery. Lights should be positioned at strategic points and exterior lights should be protected against damage.
Security systems. Detection and security systems are extremely important. Another interesting device is the smoke screen system. Once activated, this system, within seconds, fills a small area with a thick but harmless smoke, thus preventing criminals from seeing and forcing them to flee. The smoke screen system is mainly used to ______. A .prevent criminals from running out of stores. B. prevent criminals from opening the safes. C. force the criminals to give in to the police. D. force the criminals to run out of the stores.