Question: Who is Sancha Of Castile, Queen Of Aragon's father-in-law?

Knowledge 1: Sancha of Castile, Queen of Aragon
Sancha of Castile (21 September 1154/5 – 9 November 1208) was the only surviving child of King Alfonso VII of Castile by his second wife, Richeza of Poland.On January 18, 1174, she married King Alfonso II of Aragon at Zaragoza; they had at least eight children who survived into adulthood.A patroness of troubadours such as Giraud de Calanson and Peire Raymond, the queen became involved in a legal dispute with her husband concerning properties which formed part of her dower estates.In 1177 she entered the county of Ribagorza and took forcible possession of various castles and fortresses which had belonged to the crown there.After her husband died at Perpignan in 1196, Sancha was relegated to the background of political affairs by her son Peter II.She retired from court, withdrawing to the Hospitaller convent for noble ladies, the Monastery of Santa María de Sigena, at Sigena, which she had founded.There she assumed the cross of the Order of St John of Jerusalem which she wore until the end of her life.The queen mother entertained her widowed daughter Constance at Sigena prior to her leaving Aragon to marry Emperor Frederick II in 1208.She died soon afterwards, aged fifty-four, and was interred in front of the high altar of her foundation at the Monastery of Santa María de Sigena; her tomb is still there to be seen. [SEP] Knowledge 2: Alfonso II of Aragon
Alfonso II (1–25 March 1157 – 25 April 1196), called the Chaste or the Troubadour, was the King of Aragon and, as Alfons I, the Count of Barcelona from 1164 until his death.The eldest son of Count Ramon Berenguer IV of Barcelona and Queen Petronilla of Aragon, he was the first King of Aragon who was also Count of Barcelona.He was also Count of Provence, which he conquered from Douce II, from 1166 until 1173, when he ceded it to his brother, Ramon Berenguer III.His reign has been characterised by nationalistic and nostalgic Catalan historians, as "l'engrandiment occitànic" or "the Pyrenean unity": a great scheme to unite various lands on both sides of the Pyrenees under the rule of the House of Barcelona.
Knowledge 1: Sancha of Castile, Queen of Aragon
Sancha of Castile (21 September 1154/5 – 9 November 1208) was the only surviving child of King Alfonso VII of Castile by his second wife, Richeza of Poland.On January 18, 1174, she married King Alfonso II of Aragon at Zaragoza; they had at least eight children who survived into adulthood.A patroness of troubadours such as Giraud de Calanson and Peire Raymond, the queen became involved in a legal dispute with her husband concerning properties which formed part of her dower estates.In 1177 she entered the county of Ribagorza and took forcible possession of various castles and fortresses which had belonged to the crown there.After her husband died at Perpignan in 1196, Sancha was relegated to the background of political affairs by her son Peter II.She retired from court, withdrawing to the Hospitaller convent for noble ladies, the Monastery of Santa María de Sigena, at Sigena, which she had founded.There she assumed the cross of the Order of St John of Jerusalem which she wore until the end of her life.The queen mother entertained her widowed daughter Constance at Sigena prior to her leaving Aragon to marry Emperor Frederick II in 1208.She died soon afterwards, aged fifty-four, and was interred in front of the high altar of her foundation at the Monastery of Santa María de Sigena; her tomb is still there to be seen. [SEP] Knowledge 2: Maria of Aragon, Queen of Castile
Maria of Aragon was the Queen consort of Castile and Leon as the wife of John II of Castile.She was the daughter of Ferdinand I of Aragon and Eleanor of Alburquerque.
Knowledge 1: Alfonso II of Aragon
Alfonso II (1–25 March 1157 – 25 April 1196), called the Chaste or the Troubadour, was the King of Aragon and, as Alfons I, the Count of Barcelona from 1164 until his death.The eldest son of Count Ramon Berenguer IV of Barcelona and Queen Petronilla of Aragon, he was the first King of Aragon who was also Count of Barcelona.He was also Count of Provence, which he conquered from Douce II, from 1166 until 1173, when he ceded it to his brother, Ramon Berenguer III.His reign has been characterised by nationalistic and nostalgic Catalan historians, as "l'engrandiment occitànic" or "the Pyrenean unity": a great scheme to unite various lands on both sides of the Pyrenees under the rule of the House of Barcelona. [SEP] Knowledge 2: Maria of Aragon, Queen of Castile
Maria of Aragon was the Queen consort of Castile and Leon as the wife of John II of Castile.She was the daughter of Ferdinand I of Aragon and Eleanor of Alburquerque.

Answer: Ramon Berenguer IV