Explanation:

- Gautam Gambhir, a former Indian cricketer, made his One Day International (ODI) debut in Dhaka.

- Correct Answer: Option 1 - Dhaka

- Gambhir debuted against Bangladesh on April 11, 2003, in an ODI match held in Dhaka.

- This match was part of a bilateral series between India and Bangladesh.

- Option 2: Mumbai

- Mumbai is incorrect as the venue for Gambhir's ODI debut.

- The city is significant for cricket in India but not related to his debut.

- Option 3: Kolkata

- Kolkata, famous for its cricket culture, is also incorrect.

- Gambhir did not make his international debut in this city.

- Option 4: Colombo

- Colombo is in Sri Lanka and not a relevant option for Gambhir’s ODI debut.

- He did not debut there for an ODI.