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]: 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.
[EX A]: data

[EX Q]: What was the name of the person who joined in on the coup with Xianfeng's empress?, Context: These years saw an evolution in the participation of Empress Dowager Cixi (Wade–Giles: Tz'u-Hsi) in state affairs. She entered the imperial palace in the 1850s as a concubine to the Xianfeng Emperor (r. 1850–1861) and came to power in 1861 after her five-year-old son, the Tongzhi Emperor ascended the throne. She, the Empress Dowager Ci'an (who had been Xianfeng's empress), and Prince Gong (a son of the Daoguang Emperor), staged a coup that ousted several regents for the boy emperor. Between 1861 and 1873, she and Ci'an served as regents, choosing the reign title "Tongzhi" (ruling together). Following the emperor's death in 1875, Cixi's nephew, the Guangxu Emperor, took the throne, in violation of the dynastic custom that the new emperor be of the next generation, and another regency began. In the spring of 1881, Ci'an suddenly died, aged only forty-three, leaving Cixi as sole regent.
[EX A]: Prince Gong

[EX Q]: Why did Hill challenge his sentence?, Context: Traditionally, Section 1983 was of limited use for a state prisoner under sentence of death because the Supreme Court has held that habeas corpus, not Section 1983, is the only vehicle by which a state prisoner can challenge his judgment of death. In the 2006 Hill v. McDonough case, however, the United States Supreme Court approved the use of Section 1983 as a vehicle for challenging a state's method of execution as cruel and unusual punishment in violation of the Eighth Amendment. The theory is that a prisoner bringing such a challenge is not attacking directly his judgment of death, but rather the means by which that the judgment will be carried out. Therefore, the Supreme Court held in the Hill case that a prisoner can use Section 1983 rather than habeas corpus to bring the lawsuit. Yet, as Clarence Hill's own case shows, lower federal courts have often refused to hear suits challenging methods of execution on the ground that the prisoner brought the claim too late and only for the purposes of delay. Further, the Court's decision in Baze v. Rees, upholding a lethal injection method used by many states, has drastically narrowed the opportunity for relief through Section 1983.
[EX A]:
cruel and unusual punishment