Classify the relation of question with context to one of these categories: 1) award received, 2) based on, collection, 3) conflict, 4) constellation, 5) convicted of, 6) date of death, 7) director, 8) drafted by, 9) educated at, 10) medical condition, 11) military branch, 12) narrative location, 13) occupation, 14) original network, 15) parent company, 16) point in time, 17) production company, 18) residence, 19) series, 20) service entry, 21) sex or gender, 22) spouse, 23) standards body question.
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Question: Context : Erik Bruhn died in Toronto General Hospital on 1 April 1986 at the age of 57. 
Question : What sex is Erik Bruhn?

Answer: sex or gender


Question: Context : The Queen's Own Highlanders (Seaforth and Camerons), officially abbreviated ``QO HLDRS,'' was an infantry regiment of the British Army, part of the Scottish Division. 
Question : What army did Queen's Own Highlanders (Seaforth and Camerons) serve in?

Answer: military branch


Question: Context : Zagi M-91 is a submachine gun created in 1991, when the dissolution of Yugoslavia left Croatia with few or no weapons to arm their military in the time of Croatian War of Independence. 
Question : What year was Zagi M-91 introduced?

Answer:
service entry