In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

[EX Q]: Which of the following is not a common shape for helicoids: large sheets, circular, or tube-like bridges?, Context: In the helical thylakoid model, grana consist of a stack of flattened circular granal thylakoids that resemble pancakes. Each granum can contain anywhere from two to a hundred thylakoids, though grana with 1020 thylakoids are most common. Wrapped around the grana are helicoid stromal thylakoids, also known as frets or lamellar thylakoids. The helices ascend at an angle of 2025, connecting to each granal thylakoid at a bridge-like slit junction. The helicoids may extend as large sheets that link multiple grana, or narrow to tube-like bridges between grana. While different parts of the thylakoid system contain different membrane proteins, the thylakoid membranes are continuous and the thylakoid space they enclose form a single continuous labyrinth.
[EX A]: circular

[EX Q]: Why did the Ottonian dynasty get replaced by the Salian dynasty?, Context: During the early High Middle Ages, Germany was ruled by the Ottonian dynasty, which struggled to control the powerful dukes ruling over territorial duchies tracing back to the Migration period. In 1024, they were replaced by the Salian dynasty, who famously clashed with the papacy under Emperor Henry IV (r. 10841105) over church appointments as part of the Investiture Controversy. His successors continued to struggle against the papacy as well as the German nobility. A period of instability followed the death of Emperor Henry V (r. 111125), who died without heirs, until Frederick I Barbarossa (r. 115590) took the imperial throne. Although he ruled effectively, the basic problems remained, and his successors continued to struggle into the 13th century. Barbarossa's grandson Frederick II (r. 12201250), who was also heir to the throne of Sicily through his mother, clashed repeatedly with the papacy. His court was famous for its scholars and he was often accused of heresy. He and his successors faced many difficulties, including the invasion of the Mongols into Europe in the mid-13th century. Mongols first shattered the Kievan Rus' principalities and then invaded Eastern Europe in 1241, 1259, and 1287.
[EX A]: struggled to control the powerful dukes ruling over territorial duchies

[EX Q]: What did the feature do to a URL?, Context: In October 2013, the company announced the "Save a Page" feature which allows any Internet user to archive the contents of a URL. This became a threat of abuse by the service for hosting malicious binaries.
[EX A]:
archive the contents