Q: 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 2008 Research Assessment Exercise returned 26% of the 1225 staff submitted as being world-leading (4*) and a further 47% as being internationally excellent (3*). The 2008 Research Assessment Exercise also showed five subjects – Pure Mathematics, Epidemiology and Public Health, Chemical Engineering, Civil Engineering, and Mechanical, Aeronautical and Manufacturing Engineering – were assessed to be the best[clarification needed] in terms of the proportion of internationally recognised research quality.
A:
what assesment showed 1225 staff to be world-leading?