TASK DEFINITION: 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.
PROBLEM: Context : The Bill was the longest-running police procedural television series in the United Kingdom until its cancellation, and was among the longest running of any British television series. 
Question : What network did The Bill originally appear on?

SOLUTION: original network

PROBLEM: Context : The Kleinmann-Low nebula (Orion KL nebula) is the most active star forming region of the Orion Nebula. 
Question : The star/galaxy Kleinmann-Low nebula is in what constellation?

SOLUTION: constellation

PROBLEM: Context : In cryptography, the IDEA NXT algorithm (previously known as FOX) is a block cipher designed by Pascal Junod and Serge Vaudenay of EPFL (Lausanne, Switzerland). 
Question : Which is the basis of IDEA NXT?

SOLUTION:
based on