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: The use of alloys by humans started with the use of meteoric iron, a naturally occurring alloy of nickel and iron. It is the main constituent of iron meteorites which occasionally fall down on Earth from outer space. As no metallurgic processes were used to separate iron from nickel, the alloy was used as it was. Meteoric iron could be forged from a red heat to make objects such as tools, weapons, and nails. In many cultures it was shaped by cold hammering into knives and arrowheads. They were often used as anvils. Meteoric iron was very rare and valuable, and difficult for ancient people to work.

SOLUTION: What was the first man-made alloy used by humans?

PROBLEM: Passage: There is a sizeable Greek minority of about 105,000 (disputed, sources claim higher) people, in Albania. The Greek minority of Turkey, which numbered upwards of 200,000 people after the 1923 exchange, has now dwindled to a few thousand, after the 1955 Constantinople Pogrom and other state sponsored violence and discrimination. This effectively ended, though not entirely, the three-thousand-year-old presence of Hellenism in Asia Minor. There are smaller Greek minorities in the rest of the Balkan countries, the Levant and the Black Sea states, remnants of the Old Greek Diaspora (pre-19th century).

SOLUTION: What other countries don't boast of a Greek populace?

PROBLEM: Passage: Molecular studies based on DNA analysis have suggested new relationships among mammal families over the last few years. Most of these findings have been independently validated by retrotransposon presence/absence data. Classification systems based on molecular studies reveal three major groups or lineages of placental mammals- Afrotheria, Xenarthra, and Boreoeutheria- which diverged from early common ancestors in the Cretaceous. The relationships between these three lineages is contentious, and all three possible different hypotheses have been proposed with respect to which group is basal with respect to other placentals. These hypotheses are Atlantogenata (basal Boreoeutheria), Epitheria (basal Xenarthra), and Exafroplacentalia (basal Afrotheria). Boreoeutheria in turn contains two major lineages- Euarchontoglires and Laurasiatheria.

SOLUTION:
What have studies based on Boreoeutheria suggested?