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.

[Q]: Passage: To make pulp from wood, a chemical pulping process separates lignin from cellulose fibres. This is accomplished by dissolving lignin in a cooking liquor, so that it may be washed from the cellulose; this preserves the length of the cellulose fibres. Paper made from chemical pulps are also known as wood-free papers–not to be confused with tree-free paper; this is because they do not contain lignin, which deteriorates over time. The pulp can also be bleached to produce white paper, but this consumes 5% of the fibres; chemical pulping processes are not used to make paper made from cotton, which is already 90% cellulose.
[A]: What is separated from pulp to make wood?


[Q]: Passage: Since World War II, aircraft carrier designs have increased in size to accommodate a steady increase in aircraft size. The large, modern Nimitz class of US carriers has a displacement nearly four times that of the World War II–era USS Enterprise, yet its complement of aircraft is roughly the same—a consequence of the steadily increasing size and weight of military aircraft over the years. Today's aircraft carriers are so expensive that nations which operate them risk significant political, economic, and military impact if a carrier is lost, or even used in conflict.
[A]: Why have aircraft carriers increased in size since World War I?


[Q]: Passage: The greylag goose (Anser anser) was domesticated by the Egyptians at least 3000 years ago, and a different wild species, the swan goose (Anser cygnoides), domesticated in Siberia about a thousand years later, is known as a Chinese goose. The two hybridise with each other and the large knob at the base of the beak, a noticeable feature of the Chinese goose, is present to a varying extent in these hybrids. The hybrids are fertile and have resulted in several of the modern breeds. Despite their early domestication, geese have never gained the commercial importance of chickens and ducks.
[A]:
When was the greylag goose domesticated by the Romans?