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.

Input: Consider Input: Passage: Because of their long life, fast switching times, and their ability to be seen in broad daylight due to their high output and focus, LEDs have been used in brake lights for cars' high-mounted brake lights, trucks, and buses, and in turn signals for some time, but many vehicles now use LEDs for their rear light clusters. The use in brakes improves safety, due to a great reduction in the time needed to light fully, or faster rise time, up to 0.5 second faster[citation needed] than an incandescent bulb. This gives drivers behind more time to react. In a dual intensity circuit (rear markers and brakes) if the LEDs are not pulsed at a fast enough frequency, they can create a phantom array, where ghost images of the LED will appear if the eyes quickly scan across the array. White LED headlamps are starting to be used. Using LEDs has styling advantages because LEDs can form much thinner lights than incandescent lamps with parabolic reflectors.

Output: Why are non-LED lights sought after for various applications?

Input: Consider Input: Passage: The capital city of Windhoek plays a very important role in Namibia's tourism due to its central location and close proximity to Hosea Kutako International Airport. According to The Namibia Tourism Exit Survey, which was produced by the Millennium Challenge Corporation for the Namibian Directorate of Tourism, 56% of all tourists visiting Namibia during the time period, 2012 - 2013, visited Windhoek. Many of Namibia's tourism related parastatals and governing bodies such as Namibia Wildlife Resorts, Air Namibia and the Namibia Tourism Board as well as Namibia's tourism related trade associations such as the Hospitality Association of Namibia are also all headquartered in Windhoek. There are also a number of notable hotels in Windhoek such as Windhoek Country Club Resort and some international hotel chains also operate in Windhoek, such as Avani Hotels and Resorts and Hilton Hotels and Resorts.

Output: What percentage of tourists arrive in Namibia at Hosea Kutako International Airport?

Input: Consider Input: Passage: From the caliphate's north-western African bases, a series of raids on coastal areas of the Visigothic Kingdom paved the way to the permanent occupation of most of Iberia by the Umayyads (starting in 711), and on into south-eastern Gaul (last stronghold at Narbonne in 759). Hisham's reign witnessed the end of expansion in the west, following the defeat of the Arab army by the Franks at the Battle of Tours in 732. In 739 a major Berber Revolt broke out in North Africa, which was subdued only with difficulty, but it was followed by the collapse of Umayyad authority in al-Andalus. In India the Arab armies were defeated by the south Indian Chalukya dynasty and by the north Indian Pratiharas Dynasty in the 8th century and the Arabs were driven out of India. In the Caucasus, the confrontation with the Khazars peaked under Hisham: the Arabs established Derbent as a major military base and launched several invasions of the northern Caucasus, but failed to subdue the nomadic Khazars. The conflict was arduous and bloody, and the Arab army even suffered a major defeat at the Battle of Marj Ardabil in 730. Marwan ibn Muhammad, the future Marwan II, finally ended the war in 737 with a massive invasion that is reported to have reached as far as the Volga, but the Khazars remained unsubdued.
Output: What paved the way towards an occupation of the Umayyads by the Iberians?