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 : Max Matern (19 January 1902 -- 22 May 1935) was a member of the Communist Party of Germany (KPD). 
Question : Which crime led to the conviction of Max Matern?

SOLUTION: convicted of

PROBLEM: Context : The Source Family is a 2012 feature documentary film directed by Jodi Wille and Maria Demopoulos that recounts the story of Father Yod, Ya Ho Wa 13 and the Source Family. 
Question : Who served as director for The Source Family?

SOLUTION: director

PROBLEM: Context : Sir (Richard) Walter Essex (13 January 1857 -- 15 September 1941) was a British businessman and Liberal Party politician. 
Question : What was Walter Essex's occupation?

SOLUTION:
occupation