The correct answer is option 3: working of dyarchy. The Simon Commission was sent by the British Parliament to India in 1927 to review and make recommendations on the working of dyarchy in India. Dyarchy was a system of dual government introduced by the Government of India Act of 1919, which divided the responsibilities of governance between British officials and Indian ministers. The Simon Commission was tasked with assessing the impact and effectiveness of this system in practice. It was composed of seven members, all of whom were members of the British Parliament but had no representation from India. The Commission faced significant protests and opposition in India, as it was seen as an attempt to further entrench British control and deny Indian participation in the governance of their own country.