What is the ‘broken windows’ theory?

What is the ‘broken windows’ theory?
A . The theory proposed by Kelling and Wilson that leaving broken windows or other markers of decay, such as graffiti and trash, unattended or unrepaired can lead to the impression of abandonment and increase crime opportunity because no capable guardian (i.e. security presence) is observed.
B. The theory proposed by Kelling and Wilson that leaving broken windows or other markers of decay, such as graffiti and trash, unattended or unrepaired can lead to the impression of the drop in value of a site
C. The theory proposed by Kelling and Wilson that leaving broken windows or other markers of decay, such as graffiti and trash, unattended or unrepaired can lead to the impression of higher costs associated with security services
D. The theory proposed by Kelling and Wilson that leaving broken windows or other markers of decay, such as graffiti and trash, unattended or unrepaired can lead to a reduction of Law Enforcement patrolling and response to a location

Answer: A