TASK DEFINITION: In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
PROBLEM: A bit is a unit of?, Context: USB data is transmitted by toggling the data lines between the J state and the opposite K state. USB encodes data using the NRZI line coding; a 0 bit is transmitted by toggling the data lines from J to K or vice versa, while a 1 bit is transmitted by leaving the data lines as-is. To ensure a minimum density of signal transitions remains in the bitstream, USB uses bit stuffing; an extra 0 bit is inserted into the data stream after any appearance of six consecutive 1 bits. Seven consecutive received 1 bits is always an error. USB 3.0 has introduced additional data transmission encodings.

SOLUTION: data

PROBLEM: How were people ranked within a community?, Context: The original Latin word "universitas" refers in general to "a number of persons associated into one body, a society, company, community, guild, corporation, etc." At the time of the emergence of urban town life and medieval guilds, specialised "associations of students and teachers with collective legal rights usually guaranteed by charters issued by princes, prelates, or the towns in which they were located" came to be denominated by this general term. Like other guilds, they were self-regulating and determined the qualifications of their members.

SOLUTION: they were self-regulating and determined the qualifications of their members

PROBLEM: What group settled in the north?, Context: The breakup of the Carolingian Empire was accompanied by invasions, migrations, and raids by external foes. The Atlantic and northern shores were harassed by the Vikings, who also raided the British Isles and settled there as well as in Iceland. In 911, the Viking chieftain Rollo (d. c. 931) received permission from the Frankish King Charles the Simple (r. 898–922) to settle in what became Normandy.[Q] The eastern parts of the Frankish kingdoms, especially Germany and Italy, were under continual Magyar assault until the invader's defeat at the Battle of Lechfeld in 955. The breakup of the Abbasid dynasty meant that the Islamic world fragmented into smaller political states, some of which began expanding into Italy and Sicily, as well as over the Pyrenees into the southern parts of the Frankish kingdoms.

SOLUTION:
the Viking chieftain Rollo