Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.

[EX Q]: Passage: A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. A natural number greater than 1 that is not a prime number is called a composite number. For example, 5 is prime because 1 and 5 are its only positive integer factors, whereas 6 is composite because it has the divisors 2 and 3 in addition to 1 and 6. The fundamental theorem of arithmetic establishes the central role of primes in number theory: any integer greater than 1 can be expressed as a product of primes that is unique up to ordering. The uniqueness in this theorem requires excluding 1 as a prime because one can include arbitrarily many instances of 1 in any factorization, e.g., 3, 1 · 3, 1 · 1 · 3, etc. are all valid factorizations of 3. Question: Why must one be excluded in order to preserve the uniqueness of the fundamental theorem?
[EX A]: because one can include arbitrarily many instances of 1 in any factorization

[EX Q]: Passage: Warsaw's first stock exchange was established in 1817 and continued trading until World War II. It was re-established in April 1991, following the end of the post-war communist control of the country and the reintroduction of a free-market economy. Today, the Warsaw Stock Exchange (WSE) is, according to many indicators, the largest market in the region, with 374 companies listed and total capitalization of 162 584 mln EUR as of 31 August 2009. From 1991 until 2000, the stock exchange was, ironically, located in the building previously used as the headquarters of the Polish United Workers' Party (PZPR). Question: Whose former headquarters was the WSE located in until 2000?
[EX A]: Polish United Workers' Party

[EX Q]: Passage: From 2005 to 2014, there were two Major League Soccer teams in Los Angeles — the LA Galaxy and Chivas USA — that both played at the StubHub Center and were local rivals. However, Chivas were suspended following the 2014 MLS season, with a second MLS team scheduled to return in 2018. Question: When is the suspended team scheduled to return?
[EX A]:
2018