The Constituent Assembly of India adopted the design of the National Flag on 22 July 1947, just weeks before independence. This was done by resolving that the National Flag of India shall be horizontal tricolor of deep saffron, white, and dark green in equal proportion. Option A (1948) is incorrect as the flag was adopted before independence. Options C and D (1950) are also wrong as the adoption happened in 1947, not 1950.