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.

Passage: The terms used to define Greekness have varied throughout history but were never limited or completely identified with membership to a Greek state. By Western standards, the term Greeks has traditionally referred to any native speakers of the Greek language, whether Mycenaean, Byzantine or modern Greek. Byzantine Greeks called themselves Romioi and considered themselves the political heirs of Rome, but at least by the 12th century a growing number of those educated, deemed themselves the heirs of ancient Greece as well, although for most of the Greek speakers, "Hellene" still meant pagan. On the eve of the Fall of Constantinople the Last Emperor urged his soldiers to remember that they were the descendants of Greeks and Romans.
What do Easterners believe it means to belong to the Greek heritage

Passage: Another milestone in the early development of Baptist doctrine was in 1638 with John Spilsbury, a Calvinistic minister who helped to promote the strict practice of believer's baptism by immersion. According to Tom Nettles, professor of historical theology at Southern Baptist Theological Seminary, "Spilsbury's cogent arguments for a gathered, disciplined congregation of believers baptized by immersion as constituting the New Testament church gave expression to and built on insights that had emerged within separatism, advanced in the life of John Smyth and the suffering congregation of Thomas Helwys, and matured in Particular Baptists."
When did John Spilsbury create the strict practice of immersion?

Passage: Shell's primary business is the management of a vertically integrated oil company. The development of technical and commercial expertise in all stages of this vertical integration, from the initial search for oil (exploration) through its harvesting (production), transportation, refining and finally trading and marketing established the core competencies on which the company was founded. Similar competencies were required for natural gas, which has become one of the most important businesses in which Shell is involved, and which contributes a significant proportion of the company's profits. While the vertically integrated business model provided significant economies of scale and barriers to entry, each business now seeks to be a self-supporting unit without subsidies from other parts of the company.
What is the least important business for Shell?