Question: Who is Sancho Ramírez's maternal grandfather?

Knowledge 1: Sancho Ramírez
Sancho Ramírez (1042 – 4 June, 1094) was King of Aragon from 1063 until 1094 and King of Pamplona from 1076 under the name of Sancho V .He was the eldest son of Ramiro I and Ermesinda of Bigorre.His father was the first king of Aragon and an illegitimate son of Sancho III of Pamplona.He inherited the Aragonese crown from his father in 1063.Sancho Ramírez was chosen king of Pamplona by Navarrese noblemen after Sancho IV was murdered by his siblings. [SEP] Knowledge 2: Ermesinda of Bigorre
Ermesinda of Bigorre(Aragonese: "Ermisenda de Bigorra"), born Gerberga or Gisberga (1015 – 1 December 1049), was a Queen of Aragon, a daughter of Bernard-Roger, Count of Bigorre and his wife Garsenda, Heiress of Bigorre.She was a member of the House of Foix, the sister of Bernard II, Count of Bigorre, Roger I, Count of Foix, and perhaps of Stephanie who married García Sánchez III of Navarre.Gerberga married on 22 August 1036 to King Ramiro I of Aragon.After her wedding Gerberga changed her name to Ermesinda.The couple were married for thirteen years, in which time her husband elevated himself from a vassal holding scattered lands around Jaca into a "de facto" ruler of pocket-kingdom spanning the former counties of Aragon, Sobrarbe and Ribagorza, and is thereby credited with being the first King of Aragon.They had the following children:All of Ermesinda's children lived to adulthood.She died on 1 December 1049 and she was buried at the Monastery of San Juan de la Peña.Her husband remarried four years later to Agnes.
Knowledge 1: Ermesinda of Bigorre
Ermesinda of Bigorre(Aragonese: "Ermisenda de Bigorra"), born Gerberga or Gisberga (1015 – 1 December 1049), was a Queen of Aragon, a daughter of Bernard-Roger, Count of Bigorre and his wife Garsenda, Heiress of Bigorre.She was a member of the House of Foix, the sister of Bernard II, Count of Bigorre, Roger I, Count of Foix, and perhaps of Stephanie who married García Sánchez III of Navarre.Gerberga married on 22 August 1036 to King Ramiro I of Aragon.After her wedding Gerberga changed her name to Ermesinda.The couple were married for thirteen years, in which time her husband elevated himself from a vassal holding scattered lands around Jaca into a "de facto" ruler of pocket-kingdom spanning the former counties of Aragon, Sobrarbe and Ribagorza, and is thereby credited with being the first King of Aragon.They had the following children:All of Ermesinda's children lived to adulthood.She died on 1 December 1049 and she was buried at the Monastery of San Juan de la Peña.Her husband remarried four years later to Agnes. [SEP] Knowledge 2: Sancho Ramírez, Count of Ribagorza
Sancho Ramírez (before 10431105/November 1110) was an illegitimate son of King Ramiro I of Aragon and Amuña, the firstborn and brother of his namesake who would inherit the throne and reign as Sancho Ramírez.
Knowledge 1: Ermesinda of Bigorre
Ermesinda of Bigorre(Aragonese: "Ermisenda de Bigorra"), born Gerberga or Gisberga (1015 – 1 December 1049), was a Queen of Aragon, a daughter of Bernard-Roger, Count of Bigorre and his wife Garsenda, Heiress of Bigorre.She was a member of the House of Foix, the sister of Bernard II, Count of Bigorre, Roger I, Count of Foix, and perhaps of Stephanie who married García Sánchez III of Navarre.Gerberga married on 22 August 1036 to King Ramiro I of Aragon.After her wedding Gerberga changed her name to Ermesinda.The couple were married for thirteen years, in which time her husband elevated himself from a vassal holding scattered lands around Jaca into a "de facto" ruler of pocket-kingdom spanning the former counties of Aragon, Sobrarbe and Ribagorza, and is thereby credited with being the first King of Aragon.They had the following children:All of Ermesinda's children lived to adulthood.She died on 1 December 1049 and she was buried at the Monastery of San Juan de la Peña.Her husband remarried four years later to Agnes. [SEP] Knowledge 2: Ramiro II of Aragon
Ramiro II( 24 April 1086 – 16 August 1157), called the Monk, was King of Aragon from 1134 until withdrawing from public life in 1137( although he used the royal title until his death).He was the youngest son of Sancho Ramírez, King of Aragon and Navarre and Felicia of Roucy.

Answer: Bernard-Roger, Count of Bigorre