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.
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Question: Passage: The first extant Estonian book is a bilingual German-Estonian translation of the Lutheran catechism by S. Wanradt and J. Koell dating to 1535, during the Protestant Reformation period. An Estonian grammar book to be used by priests was printed in German in 1637. The New Testament was translated into southern Estonian in 1686 (northern Estonian, 1715). The two languages were united based on northern Estonian by Anton thor Helle.

Answer: Who wrote the last Estonian book? 


Question: Passage: After the Peace of Westphalia, several border territories were assigned to the United Provinces. They were federally-governed Generality Lands (Generaliteitslanden). They were Staats-Brabant (present North Brabant), Staats-Vlaanderen (present Zeeuws-Vlaanderen), Staats-Limburg (around Maastricht) and Staats-Oppergelre (around Venlo, after 1715).

Answer: In 1715 what was assigned to the United Provinces?


Question: Passage: For various reasons, the new firm operated as a dual-listed company, whereby the merging companies maintained their legal existence, but operated as a single-unit partnership for business purposes. The terms of the merger gave 60 percent ownership of the new group to the Dutch arm and 40 percent to the British. National patriotic sensibilities would not permit a full-scale merger or takeover of either of the two companies. The Dutch company, Koninklijke Nederlandsche Petroleum Maatschappij, was in charge at The Hague of production and manufacture. A British company was formed, called the Anglo-Saxon Petroleum Company, based in London, to direct the transport and storage of the products.

Answer:
What encouraged a full-scale merger of the two companies?