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.

Example Input: Passage: Historians have divided the history of Cubism into phases. In one scheme, the first phase of Cubism, known as Analytic Cubism, a phrase coined by Juan Gris a posteriori, was both radical and influential as a short but highly significant art movement between 1910 and 1912 in France. A second phase, Synthetic Cubism, remained vital until around 1919, when the Surrealist movement gained popularity. English art historian Douglas Cooper proposed another scheme, describing three phases of Cubism in his book, The Cubist Epoch. According to Cooper there was "Early Cubism", (from 1906 to 1908) when the movement was initially developed in the studios of Picasso and Braque; the second phase being called "High Cubism", (from 1909 to 1914) during which time Juan Gris emerged as an important exponent (after 1911); and finally Cooper referred to "Late Cubism" (from 1914 to 1921) as the last phase of Cubism as a radical avant-garde movement. Douglas Cooper's restrictive use of these terms to distinguish the work of Braque, Picasso, Gris (from 1911) and Léger (to a lesser extent) implied an intentional value judgement.
Example Output:  What was the last phase of Cubism known as?

Example Input: Passage: Machine vision systems often require bright and homogeneous illumination, so features of interest are easier to process. LEDs are often used for this purpose, and this is likely to remain one of their major uses until the price drops low enough to make signaling and illumination uses more widespread. Barcode scanners are the most common example of machine vision, and many low cost products use red LEDs instead of lasers. Optical computer mice are an example of LEDs in machine vision, as it is used to provide an even light source on the surface for the miniature camera within the mouse. LEDs constitute a nearly ideal light source for machine vision systems for several reasons:
Example Output:  non-LEDs are often used for what type of systems?

Example Input: Passage: Another point of interest is the Old Town. In the centre are the large Marktkirche (Church St. Georgii et Jacobi, preaching venue of the bishop of the Lutheran Landeskirche Hannovers) and the Old Town Hall. Nearby are the Leibniz House, the Nolte House, and the Beguine Tower. A very nice quarter of the Old Town is the Kreuz-Church-Quarter around the Kreuz Church with many nice little lanes. Nearby is the old royal sports hall, now called the Ballhof theatre. On the edge of the Old Town are the Market Hall, the Leine Palace, and the ruin of the Aegidien Church which is now a monument to the victims of war and violence. Through the Marstall Gate you arrive at the bank of the river Leine, where the world-famous Nanas of Niki de Saint-Phalle are located. They are part of the Mile of Sculptures, which starts from Trammplatz, leads along the river bank, crosses Königsworther Square, and ends at the entrance of the Georgengarten. Near the Old Town is the district of Calenberger Neustadt where the Catholic Basilica Minor of St. Clemens, the Reformed Church and the Lutheran Neustädter Hof- und Stadtkirche St. Johannis are located.
Example Output:
What is located in the New Town center?