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 : The United Defense M42, sometimes known as the Marlin for the manufacturer, was an American submachine gun in World War II. It was produced from 1942 to 1943 by United Defense Supply Corp. (a government-formed company specifically tasked with weapons development) for possible issue as a replacement for the Thompson submachine gun and was used by agents of the Office of Strategic Services (OSS). 
Question : In what year did United Defense M42 enter service?

Answer: service entry


Question: Context : Messier 99 was discovered by Pierre Méchain on March 17, 1781 along . 
Question : What constellation is Messier 99 in?

Answer: constellation


Question: Context : Linda Greenlaw (born December 22, 1960) is a best-selling author of books with maritime themes and the only female swordfishing boat captain on the East Coast of the United States. 
Question : What gender was Linda Greenlaw?

Answer:
sex or gender