instruction:
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.
question:
Passage: In 1872, Russian Alexander Lodygin invented an incandescent light bulb and obtained a Russian patent in 1874. He used as a burner two carbon rods of diminished section in a glass receiver, hermetically sealed, and filled with nitrogen, electrically arranged so that the current could be passed to the second carbon when the first had been consumed. Later he lived in the USA, changed his name to Alexander de Lodyguine and applied and obtained patents for incandescent lamps having chromium, iridium, rhodium, ruthenium, osmium, molybdenum and tungsten filaments, and a bulb using a molybdenum filament was demonstrated at the world fair of 1900 in Paris.
answer:
Who did not patent an incandescent light bulb in 1872?


question:
Passage: "Green" in modern European languages corresponds to about 520–570 nm, but many historical and non-European languages make other choices, e.g. using a term for the range of ca. 450–530 nm ("blue/green") and another for ca. 530–590 nm ("green/yellow").[citation needed] In the comparative study of color terms in the world's languages, green is only found as a separate category in languages with the fully developed range of six colors (white, black, red, green, yellow, and blue), or more rarely in systems with five colors (white, red, yellow, green, and black/blue). (See distinction of green from blue) These languages have introduced supplementary vocabulary to denote "green", but these terms are recognizable as recent adoptions that are not in origin color terms (much like the English adjective orange being in origin not a color term but the name of a fruit). Thus, the Thai word เขียว besides meaning "green" also means "rank" and "smelly" and holds other unpleasant associations.
answer:
What does the Thai word for green correspond to in nm?


question:
Passage: In 1634, the Mughal emperor extended his hospitality to the English traders to the region of Bengal, and in 1717 completely waived customs duties for the trade. The company's mainstay businesses were by then cotton, silk, indigo dye, saltpetre, and tea. The Dutch were aggressive competitors and had meanwhile expanded their monopoly of the spice trade in the Malaccan straits by ousting the Portuguese in 1640–41. With reduced Portuguese and Spanish influence in the region, the EIC and Dutch East India Company (VOC) entered a period of intense competition, resulting in the Anglo-Dutch Wars of the 17th and 18th centuries.
answer:

What caused the Greeks to expand their spice trade in the Malaccan straits?