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.

Input: Consider Input: Passage: The islands were occupied by a garrison of British Marines and a civilian population was gradually built up. Whalers also set up on the islands as a base for operations in the Southern Atlantic. However, the opening of the Suez Canal in 1869, together with the gradual move from sailing ships to coal-fired steam ships, increased the isolation of the islands, as they were no longer needed as a stopping port or for shelter for journeys from Europe to East Asia.

Output: By who was the sailing ships occupied?


Input: Consider Input: Passage: In the context of relativity, mass is not an additive quantity, in the sense that one can add the rest masses of particles in a system to get the total rest mass of the system. Thus, in relativity usually a more general view is that it is not the sum of rest masses, but the energy–momentum tensor that quantifies the amount of matter. This tensor gives the rest mass for the entire system. "Matter" therefore is sometimes considered as anything that contributes to the energy–momentum of a system, that is, anything that is not purely gravity. This view is commonly held in fields that deal with general relativity such as cosmology. In this view, light and other massless particles and fields are part of matter.

Output: What type of quantity is mass?


Input: Consider Input: Passage: People with an acute coronary syndrome where no ST elevation is demonstrated (non-ST elevation ACS or NSTEACS) are treated with aspirin. Clopidogrel is added in many cases, particularly if the risk of cardiovascular events is felt to be high and early PCI is being considered. Depending on whether early PCI is planned, a factor Xa inhibitor or a potentiator of antithrombin (fondaparinux or low molecular weight heparin respectively) may be added. In very high-risk scenarios, inhibitors of the platelet glycoprotein αIIbβ3a receptor such as eptifibatide or tirofiban may be used.


Output: When is clopidogrel removed?