The correct answer is option 1: Sir Edward Lutyens.

Sir Edward Lutyens was the architect responsible for designing and supervising the construction of the North and South Blocks, which are part of the Central Secretariat in Delhi. Lutyens was a prominent British architect known for his contributions to the planning and design of New Delhi, the new capital city of British India. He collaborated with Herbert Baker, another renowned architect, in designing many important buildings in Delhi. However, for the specific question about the North and South Blocks, the credit goes to Lutyens alone. Antonin Raymond and Robert Tor Tussell are not associated with the architecture of the Central Secretariat. Therefore, the correct answer is option 1.