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: Some alloys occur naturally, such as electrum, which is an alloy that is native to Earth, consisting of silver and gold. Meteorites are sometimes made of naturally occurring alloys of iron and nickel, but are not native to the Earth. One of the first alloys made by humans was bronze, which is made by mixing the metals tin and copper. Bronze was an extremely useful alloy to the ancients, because it is much stronger and harder than either of its components. Steel was another common alloy. However, in ancient times, it could only be created as an accidental byproduct from the heating of iron ore in fires (smelting) during the manufacture of iron. Other ancient alloys include pewter, brass and pig iron. In the modern age, steel can be created in many forms. Carbon steel can be made by varying only the carbon content, producing soft alloys like mild steel or hard alloys like spring steel. Alloy steels can be made by adding other elements, such as molybdenum, vanadium or nickel, resulting in alloys such as high-speed steel or tool steel. Small amounts of manganese are usually alloyed with most modern-steels because of its ability to remove unwanted impurities, like phosphorus, sulfur and oxygen, which can have detrimental effects on the alloy. However, most alloys were not created until the 1900s, such as various aluminium, titanium, nickel, and magnesium alloys. Some modern superalloys, such as incoloy, inconel, and hastelloy, may consist of a multitude of different components.

SOLUTION: What is a man-made alloy of silver and gold?

PROBLEM: Passage: The Quran describes Muhammad as "ummi", which is traditionally interpreted as "illiterate," but the meaning is rather more complex. Medieval commentators such as Al-Tabari maintained that the term induced two meanings: first, the inability to read or write in general; second, the inexperience or ignorance of the previous books or scriptures (but they gave priority to the first meaning). Muhammad's illiteracy was taken as a sign of the genuineness of his prophethood. For example, according to Fakhr al-Din al-Razi, if Muhammad had mastered writing and reading he possibly would have been suspected of having studied the books of the ancestors. Some scholars such as Watt prefer the second meaning of "ummi" - they take it to indicate unfamiliarity with earlier sacred texts.

SOLUTION: What is the most uncommon interpretation of the word "ummi" that the Quran applies to Muhammad?

PROBLEM: Passage: Violent incidents occurred throughout the Piedmont of the state as white insurgents struggled to maintain white supremacy in the face of social changes after the war and granting of citizenship to freedmen by federal constitutional amendments. After former Confederates were allowed to vote again, election campaigns from 1872 on were marked by violent intimidation of blacks and Republicans by white Democratic paramilitary groups, known as the Red Shirts. Violent incidents took place in Charleston on King Street in September 6 and in nearby Cainhoy on October 15, both in association with political meetings before the 1876 election. The Cainhoy incident was the only one statewide in which more whites were killed than blacks. The Red Shirts were instrumental in suppressing the black Republican vote in some areas in 1876 and narrowly electing Wade Hampton as governor, and taking back control of the state legislature. Another riot occurred in Charleston the day after the election, when a prominent Republican leader was mistakenly reported killed.

SOLUTION:
What weren't white Democratic paramilitary groups in Charleston known as?