Explanation:

- Option 1: New Delhi

- The Global Conference on Cyber Space (GCCS) 2017 was indeed held in New Delhi, India. This was a significant event in the digital world, marking India’s leadership in digital innovation and cyber policies on a global platform.

- Option 2: Mumbai

- Mumbai, while being a major city in India known for its commerce and finance sectors, was not the host city for the GCCS 2017.

- Option 3: Chennai

- Chennai is renowned for its information technology industry but did not host the GCCS 2017.

- Option 4: Kolkata

- Known for its cultural heritage, Kolkata was not the location for this global cyber event in 2017.

Correct Answer: Option 1: New Delhi