Answer: Challenging Joffrey's right to be king
Through a series of events, Ned Stark discovers that Joffrey and his siblings are not the offspring of Robert Baratheon. Their true father is their uncle Jamie Lannister meaning that Joffrey is not the rightful heir to the Iron Throne. In his attempt to use this information, Ned is betrayed and is executed for treason.
From Quiz: "Game of Thrones" - General Information
Answer: Nightfort
Sam read in a book that the Nightfort had a secret tunnel where Bran and his companions could get north of the Wall to the Three Eyed Raven. Shadow Tower and Eastwatch-by-the-Sea were two of the three remaining manned castles along with Castle Black. Greyguard is where Jon tried to send Janos Slynt to repair and restore, but he refused, so Jon executed Janos.
From Quiz: "Game of Thrones" Sam I Am
Answer: Varys, the Spider
At Dragonstone, in tears and furious, Daenerys tells Tyrion (Peter Dinklage) she is aware she's been betrayed. Grey Worm and the Unsullied escort Varys "the Spider" outside. Varys says to Tyrion, "I hope I am wrong" in doubting the sanity and worth of Queen Daenerys. In cold tones she pronounces him condemned to death, and commands her remaining dragon, Drogon, to sear her treasonous advisor.
She warns Tyrion that since he failed her as well, if he fails her again, it will be the last time. Tyrion nonetheless frees his captive brother Jaime (Nikolaj Coster-Waldau), hoping Jaime can smuggle Cersei out of the city, thereby surrendering it to Daenerys without bloodshed.
From Quiz: Hell is Other People
Answer: First cousins
Lyanna has had an unexpected rise to become Lady of Bear Island. Jeor Mormont, Lord Commander of the Night's Watch, was ruler of Bear Island before he willingly left to go to the Night's Watch. Jorah Mormont, Jeor's son, was ruler until he was caught selling poachers as slaves and fled to Essos. After this, Maege Mormont, younger sister to Jeor Mormont, became ruler. Maege dies (offscreen) fighting for Robb Stark and thus her daughter, Lyanna, becomes ruler.
From Quiz: "Game of Thrones" - Preparing for Season 8 #2
Answer: All of these
Tywin, Cersei, and many other people hate Tyrion mostly because he is a dwarf. It is also implied they hate him because he killed his mother. However it was not his fault, his mother died giving birth to him. Tywin never forgave him for this.
From Quiz: "Game of Thrones" - Preparing for Season 8
Answer: Lyanna Stark
In the season 6 finale ("The Winds of Winter") the popular fan theory named R+L=J was finally confirmed. During one of Bran's visions, we see the Tower of Joy and the birth of Jon. Lyanna made Ned promise her to take care of her son. In order to protect the boy, Ned raised him in Winterfell as his bastard son, avoiding talking about his mother and frequently saying that it was a prostitute.
It is proven that Lyanna is Jon's mother during this episode, but the confirmation of Rhaegar as Jon's father was later announced by HBO itself.
From Quiz: "Game of Thrones" - Jon Snow
Answer: Lyanna Mormont
During his time in Castle Black, Stannis sends letters to several Houses in the North in order to ask them to join his cause. The Lady of Bear Island replies "Bear Island knows no king but the King in the North, whose name is Stark". Jon Snow reads this same letter after Stannis shows it to him.
From Quiz: "Game of Thrones" - General Knowledge 2
Answer: Davos Seaworth
Scarred by greyscale and hidden away by her parents, Shireen's only true friend was the Onion Knight, Ser Davos, who was unaware that she'd been sacrificed to ensure her father's victory.
From Quiz: Who Killed Whom on "Game of Thrones?"
Answer: Winter is Coming
"Winter is coming" is not simply the motto of the Starks, but also an iconic phrase immediately connected to the world of "Game of Thrones".
From Quiz: "Game of Thrones" - Sigils and Mottos
Answer: King's Landing
King's Landing is the seat of the House which is ruling. It is the home of the Iron Throne, the seat of the monarch, inside the Red Keep.
From Quiz: "Game of Thrones" - Locations