Which weapon was key to Kublai Khan defeating the Sung dynasty?

Answer:
How did Kublai Khan defeat the Sung dynasty? by using siege warfare by having a larger army by building fortified cities by using armored horses Kublai Khan defeat the Sung dynasty by using siege warfare.
Explanation:
This is all I know.
Hope it helps~
Answer:
it is option C
Explanation:
i got it right on the instruction