12148
In response to the 1993 bombing , a system of road barriers , checkpoints and surveillance cameras referred to as the " ring of steel " has been maintained to control entry points to the City .
 location: City
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: City 
Answer:
 location: City