This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Example Input: Passage: Indian astronomer and mathematician Aryabhata (476-550), in his Aryabhatiya (499) introduced a number of trigonometric functions (including sine, versine, cosine and inverse sine), trigonometric tables, and techniques and algorithms of algebra. In 628 AD, Brahmagupta suggested that gravity was a force of attraction. He also lucidly explained the use of zero as both a placeholder and a decimal digit, along with the Hindu-Arabic numeral system now used universally throughout the world. Arabic translations of the two astronomers' texts were soon available in the Islamic world, introducing what would become Arabic numerals to the Islamic World by the 9th century. During the 14th–16th centuries, the Kerala school of astronomy and mathematics made significant advances in astronomy and especially mathematics, including fields such as trigonometry and analysis. In particular, Madhava of Sangamagrama is considered the "founder of mathematical analysis". Question: What did Brahmagupta use the number zero for?
Example Output: a placeholder and a decimal digit

Example Input: Passage: West's musical career has been defined by frequent stylistic shifts, and has seen him develop and explore a variety of different musical approaches and genres throughout his work. When asked about his musical inspirations, he has named A Tribe Called Quest, Stevie Wonder, Michael Jackson, George Michael, LL Cool J, Phil Collins and Madonna as early interests. He has further described musician David Bowie as one of his "most important inspirations," and named producer Puff Daddy as the "most important cultural figure in my life." Early in his career, West pioneered a style of production dubbed "chipmunk soul" which utilized pitched-up vocal samples, usually from soul and R&B songs, along with his own drums and instrumentation. His first major release featuring his trademark soulful vocal sampling style was "This Can't Be Life", a track from Jay-Z’s The Dynasty: Roc La Familia. West has said that Wu-Tang Clan producer RZA influenced him in his style, and has named Wu-Tang rappers Ghostface Killah and Ol' Dirty Bastard as inspirations. RZA spoke positively of the comparisons, stating in an interview for Rolling Stone, "All good. I got super respect for Kanye [...] [he] is going to inspire people to be like him." West further developed his style on his 2004 debut album, The College Dropout. After a rough version was leaked, he meticulously refined the production, adding string arrangements, gospel choirs, and improved drum programming. Question: Who was Kanye's greatest cultural figure?
Example Output: Puff Daddy

Example Input: Passage: From its base in India, the Company had also been engaged in an increasingly profitable opium export trade to China since the 1730s. This trade, illegal since it was outlawed by the Qing dynasty in 1729, helped reverse the trade imbalances resulting from the British imports of tea, which saw large outflows of silver from Britain to China. In 1839, the confiscation by the Chinese authorities at Canton of 20,000 chests of opium led Britain to attack China in the First Opium War, and resulted in the seizure by Britain of Hong Kong Island, at that time a minor settlement. Question: The First Opium War led to Britain seizing what island?
Example Output:
Hong Kong