Detailed Instructions: This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
See one example below:
Problem: Passage: In 1763, Spain traded Florida to the Kingdom of Great Britain for control of Havana, Cuba, which had been captured by the British during the Seven Years' War. It was part of a large expansion of British territory following the country's victory in the Seven Years' War. Almost the entire Spanish population left, taking along most of the remaining indigenous population to Cuba. The British soon constructed the King's Road connecting St. Augustine to Georgia. The road crossed the St. Johns River at a narrow point, which the Seminole called Wacca Pilatka and the British named "Cow Ford", both names ostensibly reflecting the fact that cattle were brought across the river there.
Solution: Who owned Cuba after the Eight Years War?
Explanation: This question appears to be relevant to the passage as both involves words such as 'Cuba' and 'War' which also exist in the passage. The passage mentions that "after the war, almost the entire Spanish population left, taking along most of the remaining indigenous population to Cuba". This information is not sufficient to conclude that which country owned cuba.

Problem: Passage: As of 2011, there have been six series Digimon Adventure, the follow-up sequel Digimon Adventure 02, Digimon Tamers, Digimon Frontier, Digimon Data Squad and Digimon Fusion. The first two series take place in the same fictional universe, but the third, fourth, fifth and sixth each occupy their own unique world. Each series is commonly based on the original storyline but things are added to make them unique. However, in Tamers, the Adventure universe is referred to as a commercial enterprise a trading card game in Japan, plus a show-within-a-show in the English dub. It also features an appearance by a character from the Adventure universe. In addition, each series has spawned assorted feature films. Digimon still shows popularity, as new card series, video games, and movies are still being produced and released: new card series include Eternal Courage, Hybrid Warriors, Generations, and Operation X; the video game, Digimon Rumble Arena 2; and the previously unreleased movies Revenge of Diaboromon, Runaway Locomon, Battle of Adventurers, and Island of Lost Digimon. In Japan, Digital Monster X-Evolution, the eighth TV movie, was released on January 3, 2005, and on December 23, 2005 at Jump Festa 2006, the fifth series, Digimon Savers was announced for Japan to begin airing after a three-year hiatus of the show. A sixth television series, Digimon Xros Wars, began airing in 2010, and was followed by a second season, which started on October 2, 2011 as a direct sequel to Digimon Xros Wars.
Solution:
How many series of aired as of 2001?