Which best describes a preventative measure against terrorism?

Increased surveillance in public areas is a comprehensive preventative measure against terrorism because it involves actively monitoring potential threats and suspicious behavior before any harmful act can take place. This measure can deter individuals from attempting to commit violence or engage in terrorist activities, as the presence of surveillance often increases the risk of detection and apprehension. Surveillance can include CCTV cameras, patrols by security personnel, and real-time monitoring of public spaces, which collectively enhance public safety and allow for quicker responses to any emerging threats.

Other measures, while helpful, are more reactive or limited in scope. For instance, using metal detectors at entrances primarily addresses the threat of weapons but doesn’t encompass broader surveillance of the environment. Relying solely on emergency response teams is crucial for response and mitigation after an incident occurs but doesn’t prevent an attack from happening. Similarly, limiting access to buildings after hours can enhance security, but it also does not encompass the comprehensive monitoring of public areas that surveillance offers. Thus, increased surveillance stands out as a proactive, effective approach in the framework of antiterrorism strategies.