You will be given a context, a subject and a relation. Your task is to generate a question based on the subject and relation. The generated question should include the given subject. Try to use a minimum number of words that are not present in either context, subject or relation while generating question.

Context : JBTV is currently on broadcast television WJYS-62 in Chicago Wednesday nights at 11pm with New Music Videos and live JBTV performances. 
Subject : JBTV 
Relation : original network
Which channel broadcast JBTV?

Context : The Muppet Christmas Carol is a 1992 American musical fantasy-comedy film and an adaptation of Charles Dickens's 1843 novel A Christmas Carol. 
Subject : The Muppet Christmas Carol 
Relation : based on
Which is the basis of The Muppet Christmas Carol?

Context : Plan 9 from User Space (also plan9port or p9p) is a port of many Plan 9 from Bell Labs libraries and applications to Unix-like operating systems. 
Subject : Plan 9 from User Space 
Relation : based on

The Plan 9 from User Space is based upon what?