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: Prior to Confederation in 1867, residents of the colonies in what is now Canada served as regular members of French and British forces and in local militia groups. The latter aided in the defence of their respective territories against attacks by other European powers, Aboriginal peoples, and later American forces during the American Revolutionary War and War of 1812, as well as in the Fenian raids, Red River Rebellion, and North-West Rebellion. Consequently, the lineages of some Canadian army units stretch back to the early 19th century, when militia units were formed to assist in the defence of British North America against invasion by the United States.
A:
When was the Confederation established?