Question: Who is Cao Li's paternal grandfather?

Knowledge 1: Cao Li
Cao Li (208 – May or June 229) was a prince in the state of Cao Wei in the Three Kingdoms period of China.He was a son of Cao Pi, the first emperor of Wei.His mother, Consort Xu (徐姬), was a concubine of Cao Pi.He had two full sisters: the elder one was Princess Linfen (臨汾公主) while the younger one, who was unnamed, died early.Cao Li was enfeoffed as the Duke of Qin (秦公) in 221, with his dukedom in Jingzhao Commandery (京兆郡).In 222, he was elevated to the status of Prince of Jingzhao (京兆王).In 225, his title was changed to Prince of Yuancheng (元城王).He died in 229 during the reign of his half-brother Cao Rui.In 231, Cao Rui designated Cao Ti (曹悌), a son of Cao Kai (曹楷) and grandson of Cao Zhang, as Cao Li's heir; Cao Ti thus became the new Prince of Yuancheng.In 232, Cao Ti's title was changed to Prince of Liang (梁王).Throughout the reigns of the subsequent Wei emperors, the number of taxable households in Cao Ti's princedom increased until it reached 4,500. [SEP] Knowledge 2: Cao Pi
Cao Pi  (– 29 June 226), courtesy name Zihuan, was the first emperor of the state of Cao Wei in the Three Kingdoms period of China.He was the second son of Cao Cao, a warlord who lived in the late Eastern Han dynasty, but the eldest son among all the children born to Cao Cao by his concubine (later wife), Lady Bian.According to some historical records, he was often in the presence of court officials in order to gain their support.He was mostly in charge of defence at the start of his career.After the defeat of Cao Cao's rival Yuan Shao at the Battle of Guandu, he took Yuan Xi's widow, Lady Zhen, as a concubine, but in 221 Lady Zhen died and Guo Nüwang became empress.On 25 November 220, Cao Pi forced Emperor Xian, the last ruler of the Eastern Han dynasty, to abdicate in his favour, after which on 11 December 220 he proclaimed himself emperor and established the state of Cao Wei.Cao Pi continued the wars against the states of Shu Han and Eastern Wu, founded by his father's rivals Liu Bei and Sun Quan respectively, but did not make significant territorial gain in the battles.Unlike his father, Cao Pi concentrated most of his efforts on internal administration rather than on waging wars against his rivals.During his reign, he formally established Chen Qun's nine-rank system as the base for civil service nomination, which drew many talents into his government.On the other hand, he drastically reduced the power of princes, stripping off their power to oppose him, but at the same time, rendering them unable to assist the emperor if a crisis arose within the state.After Cao Pi's death, his successor Cao Rui granted him the posthumous name "Emperor Wen" and the temple name "Shizu".Cao Pi was also an accomplished poet and scholar, just like his father Cao Cao and his younger brother Cao Zhi.He wrote "Yan Ge Xing" (燕歌行), the first Chinese poem in the style of seven syllables per line (七言詩).He also wrote over a hundred articles on various subjects.
Knowledge 1: Cao Pi
Cao Pi  (– 29 June 226), courtesy name Zihuan, was the first emperor of the state of Cao Wei in the Three Kingdoms period of China.He was the second son of Cao Cao, a warlord who lived in the late Eastern Han dynasty, but the eldest son among all the children born to Cao Cao by his concubine (later wife), Lady Bian.According to some historical records, he was often in the presence of court officials in order to gain their support.He was mostly in charge of defence at the start of his career.After the defeat of Cao Cao's rival Yuan Shao at the Battle of Guandu, he took Yuan Xi's widow, Lady Zhen, as a concubine, but in 221 Lady Zhen died and Guo Nüwang became empress.On 25 November 220, Cao Pi forced Emperor Xian, the last ruler of the Eastern Han dynasty, to abdicate in his favour, after which on 11 December 220 he proclaimed himself emperor and established the state of Cao Wei.Cao Pi continued the wars against the states of Shu Han and Eastern Wu, founded by his father's rivals Liu Bei and Sun Quan respectively, but did not make significant territorial gain in the battles.Unlike his father, Cao Pi concentrated most of his efforts on internal administration rather than on waging wars against his rivals.During his reign, he formally established Chen Qun's nine-rank system as the base for civil service nomination, which drew many talents into his government.On the other hand, he drastically reduced the power of princes, stripping off their power to oppose him, but at the same time, rendering them unable to assist the emperor if a crisis arose within the state.After Cao Pi's death, his successor Cao Rui granted him the posthumous name "Emperor Wen" and the temple name "Shizu".Cao Pi was also an accomplished poet and scholar, just like his father Cao Cao and his younger brother Cao Zhi.He wrote "Yan Ge Xing" (燕歌行), the first Chinese poem in the style of seven syllables per line (七言詩).He also wrote over a hundred articles on various subjects. [SEP] Knowledge 2: Duke Gong of Cao
Duke Gong of Cao (? – 618 BCE)  was the seventeenth ruler of the vassal State of Cao during the Chinese Spring and Autumn period (770 – 475 BCE).Born Ji Xiang (姬襄), he was the son of Duke Zhao of Cao.In 637 BCE, during the exile of Chong’er, son of Duke Xian of Jin, Duke Gong heard that Chong’er suffered from fused ribs and wanted to see for himself.Chong’er caught Duke Gong spying on him whilst he bathed and described the Duke as a man of “unbelievable rudeness”.After Chong’er became Duke Wen of Jin and one of the Five Hegemons, in 632 he used Duke Gòng's previous rudeness as an excuse to overthrow the State of Cao.Duke Gòng was captured by the State of Jin but later released.After Duke Gong of Cao died in 618 BCE, his son Duke Wen of Cao became ruler.
Knowledge 1: Cao Li
Cao Li (208 – May or June 229) was a prince in the state of Cao Wei in the Three Kingdoms period of China.He was a son of Cao Pi, the first emperor of Wei.His mother, Consort Xu (徐姬), was a concubine of Cao Pi.He had two full sisters: the elder one was Princess Linfen (臨汾公主) while the younger one, who was unnamed, died early.Cao Li was enfeoffed as the Duke of Qin (秦公) in 221, with his dukedom in Jingzhao Commandery (京兆郡).In 222, he was elevated to the status of Prince of Jingzhao (京兆王).In 225, his title was changed to Prince of Yuancheng (元城王).He died in 229 during the reign of his half-brother Cao Rui.In 231, Cao Rui designated Cao Ti (曹悌), a son of Cao Kai (曹楷) and grandson of Cao Zhang, as Cao Li's heir; Cao Ti thus became the new Prince of Yuancheng.In 232, Cao Ti's title was changed to Prince of Liang (梁王).Throughout the reigns of the subsequent Wei emperors, the number of taxable households in Cao Ti's princedom increased until it reached 4,500. [SEP] Knowledge 2: Duke Gong of Cao
Duke Gong of Cao (? – 618 BCE)  was the seventeenth ruler of the vassal State of Cao during the Chinese Spring and Autumn period (770 – 475 BCE).Born Ji Xiang (姬襄), he was the son of Duke Zhao of Cao.In 637 BCE, during the exile of Chong’er, son of Duke Xian of Jin, Duke Gong heard that Chong’er suffered from fused ribs and wanted to see for himself.Chong’er caught Duke Gong spying on him whilst he bathed and described the Duke as a man of “unbelievable rudeness”.After Chong’er became Duke Wen of Jin and one of the Five Hegemons, in 632 he used Duke Gòng's previous rudeness as an excuse to overthrow the State of Cao.Duke Gòng was captured by the State of Jin but later released.After Duke Gong of Cao died in 618 BCE, his son Duke Wen of Cao became ruler.

Answer: Cao Cao