In which dynasty did the biggest migration tide from north to south in China occur?

Choose D Song, more accurately, in the period when the Song Dynasty alternated, that is, the period when the Northern Song Dynasty perished and the Southern Song Dynasty was just established. Because the Jin people invaded the south and destroyed the Northern Song Dynasty, many people in the Northern Song Dynasty fled to the south. The first emperor of the Southern Song Dynasty, as well as troops and ministers, moved from the north to the south.