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.
--------
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 : ``Vendetta for a Dead Man'' is the twenty fourth episode of the popular 1969 ITC British television series Randall and Hopkirk (Deceased) starring Mike Pratt, Kenneth Cope and Annette Andre. 
Question : Which series was Vendetta for a Dead Man in?

Answer: series


Question: Context : ``Tornado Girl'' is the eighth episode in the third season, the 49th episode overall, of the American dramedy series Ugly Betty, which aired on November 13, 2008. 
Question : Which series was Tornado Girl in?

Answer:
series