The Simon Commission was appointed to look into the working of the Government of India Act, 1919. The Government of India Act, 1919, also known as the Montagu-Chelmsford Reforms, was a significant constitutional reform that aimed to give Indians a greater role in the governance of their country. The Act introduced the concept of dyarchy, which divided the powers of the government between the British and Indian officials.

Option 1, Indian Councils Act, 1892, is incorrect because the Simon Commission was not specifically appointed to examine this act. The Indian Councils Act, 1892 was a precursor to later acts but did not carry the same scope as the Government of India Act, 1919.

Option 2, Government of India Act, 1909, is also incorrect because the Simon Commission was not appointed to assess the working of this act. The Government of India Act, 1909, commonly known as the Morley-Minto Reforms, introduced some limited reforms but did not go as far as the Montagu-Chelmsford Reforms.

Option 4, Government of India Act, 1935, is incorrect as well. The Simon Commission was set up before the Government of India Act, 1935,