Project Tiger, a major wildlife conservation initiative in India, is widely reported to have been formally launched on April 1, 1973. However, the Indian Board for Wildlife recommended Project Tiger in 1972, following the first all-India tiger census conducted in the same year which highlighted a drastic decline in tiger populations. In the context of the provided options, 1972 likely refers to the foundational year of the initiative, including the crucial census and recommendation that led to the project's launch.