Option 1 -> Dr. S. Somnath was the previous ISRO Chairman who served before January 2025, known for leading successful missions like Chandrayaan-3.
Option 2 -> Dr. K. Sivan served as ISRO Chairman from 2018 to 2022, during which Chandrayaan-2 mission was conducted.
Option 3 -> Dr. A. S. Kiran Kumar was ISRO Chairman from 2015 to 2018, overseeing multiple satellite launches.
Option 4 -> Dr. V. Narayanan was appointed as the new Chairman of ISRO in January 2025, succeeding Dr. S. Somnath.
Hence, Option 4: Dr. V. Narayanan -> He took charge as the 11th Chairman of ISRO in January 2025, bringing extensive experience in rocket and propulsion systems, having previously served as Director of the Liquid Propulsion Systems Centre -> correct