Explanation:

- The Kartarpur Corridor is a significant initiative connecting the Sikh holy sites in India and Pakistan, allowing pilgrims to travel visa-free to the final resting place of Guru Nanak Dev, the founder of Sikhism.

- Option 1, Narendra Modi:

- Narendra Modi, the Prime Minister of India, inaugurated the Kartarpur Corridor on November 9, 2019, and flagged off the first set of pilgrims.

- Option 2, Amarinder Singh:

- Amarinder Singh, then Chief Minister of Punjab, played an important role in the ceremonies but did not inaugurate the corridor.

- Option 3, Ram Nath Kovind:

- Ram Nath Kovind was the President of India at the time, but was not directly involved in the inauguration.

- Option 4, Manmohan Singh:

- Former Prime Minister Manmohan Singh attended the inaugural ceremony as a distinguished guest.