TASK DEFINITION: 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.
PROBLEM: Passage: After the World Cup, the most important international football competitions are the continental championships, which are organised by each continental confederation and contested between national teams. These are the European Championship (UEFA), the Copa América (CONMEBOL), African Cup of Nations (CAF), the Asian Cup (AFC), the CONCACAF Gold Cup (CONCACAF) and the OFC Nations Cup (OFC). The FIFA Confederations Cup is contested by the winners of all six continental championships, the current FIFA World Cup champions and the country which is hosting the Confederations Cup. This is generally regarded as a warm-up tournament for the upcoming FIFA World Cup and does not carry the same prestige as the World Cup itself. The most prestigious competitions in club football are the respective continental championships, which are generally contested between national champions, for example the UEFA Champions League in Europe and the Copa Libertadores in South America. The winners of each continental competition contest the FIFA Club World Cup.

SOLUTION: What does UEFA Stand against?

PROBLEM: Passage: As heirs of the Dominican priory of Poissy in France, the Dartford sisters were also heirs to a tradition of profound learning and piety. Sections of translations of spiritual writings in Dartford's library, such as Suso's Little Book of Eternal Wisdom and Laurent du Bois' Somme le Roi, show that the "ghoostli" link to Europe was not lost in the crossing of the Channel. It survived in the minds of the nuns. Also, the nuns shared a unique identity with Poissy as a religious house founded by a royal house. The English nuns were proud of this heritage, and aware that many of them shared in England's great history as members of the noble class, as seen in the next chapter.

SOLUTION: What priory were the Dartford sisters not heirs to?

PROBLEM: Passage: When the alloy cools and solidifies (crystallizes), its mechanical properties will often be quite different from those of its individual constituents. A metal that is normally very soft and malleable, such as aluminium, can be altered by alloying it with another soft metal, like copper. Although both metals are very soft and ductile, the resulting aluminium alloy will be much harder and stronger. Adding a small amount of non-metallic carbon to iron produces an alloy called steel. Due to its very-high strength and toughness (which is much higher than pure iron), and its ability to be greatly altered by heat treatment, steel is one of the most common alloys in modern use. By adding chromium to steel, its resistance to corrosion can be enhanced, creating stainless steel, while adding silicon will alter its electrical characteristics, producing silicon steel.

SOLUTION:
What is produced by adding metallic carb and iron?