Question: Who is Yao Hong's paternal grandfather?
Sentence (from "Yao Hong"): (Emperor Wenzhao), who was already regarded as kind but weak during his father's reign, and after his father's death, with the state already weakened by attacks by the rebel Xia state and with his brothers and cousins repeatedly rebelling, the Jin general Liu Yu took advantage of Yao Hong's weaknesses to conquer Later Qin.
Relevant evidence: No