Explanation:

- Option 1: R K Singh

- R K Singh was the Union Minister of Power and New and Renewable Energy in India.

- He was re-elected as President of the International Solar Alliance (ISA) in October 2022.

- Option 2: Narendra Modi

- He is the Prime Minister of India, not the President of ISA.

- Option 3: Amit Shah

- Amit Shah is the Minister of Home Affairs in India and is not associated with the ISA presidency.

- Option 4: Kiren Rijiju

- Kiren Rijiju is an Indian politician serving various ministerial roles but not related to ISA.

- Option 5: Amitabh Kant

- He served as CEO of NITI Aayog and not relevant to the ISA role.