The mobile application Digicop, launched to help trace stolen mobile phones and vehicles, was introduced by the police commissioner of which Indian city?

Introduction / Context:
Indian police forces increasingly use technology to fight crime and provide citizen friendly services. Digicop is a mobile application designed to help the public check whether a mobile phone or vehicle is reported as stolen and to assist in recovering property. This question asks which city's police commissioner launched the Digicop app.

Given Data / Assumptions:
- The app mentioned is Digicop.
- It was launched by a city police commissioner as a public service tool.
- Options list four cities: Hyderabad, Chennai, Kolkata and Lucknow.
- The task is to recall which city's police force was associated with this initiative.

Concept / Approach:
The Chennai City Police launched the Digicop app to make information about stolen mobile phones and vehicles accessible to citizens. The app is linked to the central database of crime records and allows users to check whether the IMEI number of a mobile phone appears in the list of stolen items. Therefore, the correct city associated with Digicop is Chennai.

Step-by-Step Solution:
Step 1: Recognise Digicop as an app name linked with policing and digital technology. Step 2: Recall news reports or exam notes that identified Chennai Police as the organisation behind Digicop. Step 3: Compare this recollection with the cities listed in the options. Step 4: Select Chennai as the correct answer.

Verification / Alternative check:
To verify, think of media coverage that showed the Chennai Police Commissioner demonstrating the app and explaining how citizens could use IMEI numbers to find whether a device was stolen. These reports typically mentioned Chennai prominently in headlines about Digicop. No such association was highlighted for Hyderabad, Kolkata or Lucknow in relation to this specific app name.

Why Other Options Are Wrong:
- Hyderabad: Although it also adopts technology in policing, it was not the city that launched the Digicop app.
- Kolkata: Has its own set of digital initiatives, but Digicop is specifically linked to Chennai.
- Lucknow: The capital of Uttar Pradesh, but not the city associated with this particular application.

Common Pitfalls:
Because many large cities are rolling out apps and online systems, students may confuse which tool belongs to which police force. Some may also focus on the name Digicop and assume it relates to a city they hear frequently in tech news, such as Hyderabad. To avoid mixing them, link Digicop clearly with Chennai Police and with the idea of checking stolen phones through IMEI numbers.

Final Answer:
The Digicop mobile application was launched by the Police Commissioner of Chennai.