The correct answer is option 3. January 26 was selected as the date for the inauguration of the Constitution because the Congress had observed it as the Independence Day in 1930. This day holds great significance in India`s struggle for independence as it was on January 26, 1930, that the Congress declared Purna Swaraj or complete independence from British rule. Hence, this date was chosen to symbolize the culmination of India`s long journey towards freedom and the beginning of a new era as a sovereign nation. Option 1 states that it was considered an auspicious day, but there is no mention of this reason in the question. Option 2 is incorrect as the Quit India Movement started in 1942, which is unrelated to the date. Option 4 is incorrect as option 3 is the correct answer.