Question: Who is Hedwig Of Münsterberg-Oels's maternal grandfather?

Knowledge 1: Hedwig of Münsterberg-Oels
Hedwig of Munsterberg-Oels (10/12 June 1508, Oleśnica – 28 November 1531, Legnica) was born Duchess of Münsterberg and Oleśnica and Countess of Kladsko and by marriage Margravine of Brandenburg-Ansbach-Kulmbach.Hedwig was a daughter of Duke Charles I of Münsterberg-Oels, who was a grandson of the King George of Bohemia.Her mother was Anna of Sagan, a daughter of John II, the last Duke of Żagań (Sagan).On 9 January 1525 Hedwig married Margrave George of Brandenburg-Ansbach-Kulmbach.She was George's second wife.The marriage produced two daughters:Hedwig died in Legnica (Liegnitz), where she was buried. [SEP] Knowledge 2: Anna of Sagan
Anna of Sagan (Polish: "Anna żagańska",Czech: "Anna Zaháňská", also "Hlohovsko-Zaháňská" or "Zaháňsko-Hlohovská")(b. ca.1480, d. 27 or 28 October 1541) was the last surviving member of the Głogów-Żagań branch of the Silesian Piasts family, and by marriage duchess of Münsterberg and Oels.She was the daughter of Prince Jan II the Mad.On 7 January 1488 she married Duke Charles I of Münsterberg-Oels, with whom she had twelve children:She died on 27 or 28 October 1541 and was buried alongside her husband in the parish church of St. Anna in Frankenstein.
Knowledge 1: Anna of Sagan
Anna of Sagan (Polish: "Anna żagańska",Czech: "Anna Zaháňská", also "Hlohovsko-Zaháňská" or "Zaháňsko-Hlohovská")(b. ca.1480, d. 27 or 28 October 1541) was the last surviving member of the Głogów-Żagań branch of the Silesian Piasts family, and by marriage duchess of Münsterberg and Oels.She was the daughter of Prince Jan II the Mad.On 7 January 1488 she married Duke Charles I of Münsterberg-Oels, with whom she had twelve children:She died on 27 or 28 October 1541 and was buried alongside her husband in the parish church of St. Anna in Frankenstein. [SEP] Knowledge 2: Henry II, Duke of Münsterberg-Oels
Henry II of Münsterberg-Oels (also known as:"Henry II of Poděbrady", or , ; 29 March 1507 – 2 August 1548, Bierutów) was from 1536 to 1542 Duke of Münsterberg and of Oels ("Oleśnica") and from 1542 to 1548 Duke of Bernstadt ("Bierutów").He also held the title of Count of Glatz ("Kladsko"), though he never actually ruled the County itself.
Knowledge 1: Anna of Sagan
Anna of Sagan (Polish: "Anna żagańska",Czech: "Anna Zaháňská", also "Hlohovsko-Zaháňská" or "Zaháňsko-Hlohovská")(b. ca.1480, d. 27 or 28 October 1541) was the last surviving member of the Głogów-Żagań branch of the Silesian Piasts family, and by marriage duchess of Münsterberg and Oels.She was the daughter of Prince Jan II the Mad.On 7 January 1488 she married Duke Charles I of Münsterberg-Oels, with whom she had twelve children:She died on 27 or 28 October 1541 and was buried alongside her husband in the parish church of St. Anna in Frankenstein. [SEP] Knowledge 2: Karl Friedrich I, Duke of Münsterberg-Oels
Karl Friedrich I of Münsterberg-Oels (also: Karl Friedrich I of Poděbrady; or ; ; 18 October 1593, Oleśnica – 31 May 1647, Oleśnica) was Duke of Oels from 1617 to 1647 and Duke of Bernstadt from 1639 to 1647.He also held the titles of Duke of Münsterberg and Count of Glatz.

Answer: Jan II the Mad