The correct answer to the question "Who is the Chairman of the second Administrative Reforms Commission?" is option 3, M. Veerappa Moily.
Option 1, Bimal Jalan, is not the correct answer. Bimal Jalan is an Indian economist and a former Governor of the Reserve Bank of India. He has not served as the Chairman of the second Administrative Reforms Commission.
Option 2, Dr. Karan Singh, is also not the correct answer. Dr. Karan Singh is an Indian politician, diplomat, and scholar, but he has not served as the Chairman of the second Administrative Reforms Commission.
Option 4, Ahmed Patel, is not the correct answer either. Ahmed Patel was an Indian politician and a senior leader of the Indian National Congress party, but he has not served as the Chairman of the second Administrative Reforms Commission.
Therefore, the correct answer is option 3, M. Veerappa Moily. M. Veerappa Moily is an Indian politician and a former Chief Minister of Karnataka. He served as the Chairman of the second Administrative Reforms Commission, which was constituted by the Government of India in 2005 to recommend measures for improving the public administration system in the country.