Who defeated the last song emperor of china?

genghis khan
kublai khan
tang taizong
emperor taizu

Kublai Khan

Explanation:

Kublai Khan was the fifth and last great khan (1260-1294) of the Mongol Empire and the first Chinese emperor of the Yuan dynasty (1271-1294). He was the second son of Tolui and Sorgaqtani and grandson of Genghis Khan. The civil war between him and his brother Ariq Boke for the succession of his older brother Möngke (died in 1259) marked the end of a unified empire.

In 1271 Kublai officially created the Yuan Dynasty, and established the new capital at Dadu (present-day Beijing) the following year. To unify China, Kublai began a huge offensive against the last remnants of the Song dynasty in southern China, and ended his conquest of China in 1279. As emperor of China, Kublai worked to minimize the influences of the regional governors who had immense power before and during the Song dynasty. His distrust of the Han ethnic group caused him to appoint officers from other ethnic groups.

i would say b probably

the 2nd option is the answer