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.

[Q]: Context : A computer game based on The Crystal Maze was developed by Digital Jellyfish Design and released in 1993 by Sherston Software for RISC OS on the Acorn Archimedes, and subsequently for the PC. 
Question : What network aired The Crystal Maze?
[A]: original network


[Q]: Context : Early Edition is an American television drama series that aired on CBS broadcast network from September 28, 1996 to May 27, 2000. 
Question : What network does Early Edition air on?
[A]: original network


[Q]: Context : The Midland Railway 156 Class was a class of 2-4-0 tender engines built at Derby Works between 1866--1874. 
Question : What year was the service entry date for Midland Railway 156 Class?
[A]:
service entry