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: Blues rock acts that pioneered the sound included Cream, The Jimi Hendrix Experience, and The Jeff Beck Group. Cream, in songs like "I Feel Free" (1966) combined blues rock with pop and psychedelia, particularly in the riffs and guitar solos of Eric Clapton. Jimi Hendrix produced a form of blues-influenced psychedelic rock, which combined elements of jazz, blues and rock and roll. From 1967 Jeff Beck brought lead guitar to new heights of technical virtuosity and moved blues rock in the direction of heavy rock with his band, The Jeff Beck Group. Dave Davies of The Kinks, Keith Richards of The Rolling Stones, Pete Townshend of The Who, Hendrix, Clapton and Beck all pioneered the use of new guitar effects like phasing, feedback and distortion. The Beatles began producing songs in the new hard rock style beginning with the White Album in 1968 and, with the track "Helter Skelter", attempted to create a greater level of noise than the Who. Stephen Thomas Erlewine of AllMusic has described the "proto-metal roar" of "Helter Skelter," while Ian MacDonald argued that "their attempts at emulating the heavy style were without exception embarrassing."
Who was a hard rock act that pioneered the blues sound?

Passage: In 1797, Patrick Colquhoun was able to persuade the West Indies merchants who operated at the Pool of London on the River Thames, to establish a police force at the docks to prevent rampant theft that was causing annual estimated losses of £500,000 worth of cargo. The idea of a police, as it then existed in France, was considered as a potentially undesirable foreign import. In building the case for the police in the face of England's firm anti-police sentiment, Colquhoun framed the political rationale on economic indicators to show that a police dedicated to crime prevention was "perfectly congenial to the principle of the British constitution." Moreover, he went so far as to praise the French system, which had reached "the greatest degree of perfection" in his estimation.
Who convinced the East Indies merchants in London to establish police?

Passage: The rainforest contains several species that can pose a hazard. Among the largest predatory creatures are the black caiman, jaguar, cougar, and anaconda. In the river, electric eels can produce an electric shock that can stun or kill, while piranha are known to bite and injure humans. Various species of poison dart frogs secrete lipophilic alkaloid toxins through their flesh. There are also numerous parasites and disease vectors. Vampire bats dwell in the rainforest and can spread the rabies virus. Malaria, yellow fever and Dengue fever can also be contracted in the Amazon region.

Which animal living in the Amazon River produces a mild shock?