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.

Context : TAROM Flight 371 was an Airbus A310 that crashed near Baloteşti in Romania on 31 March 1995. 
Question : When did TAROM Flight 371 occur?
point in time

Context : Hans von Freden was born on 18 March 1892 in Berlin. 
Question : In which war did Hans von Freden fought?
conflict

Context : Following on from the previous volume, Explorers on the Moon, The Calculus Affair was created with the aid of the Hergé's team of artists at Studios Hergé. 
Question : What series is The Calculus Affair a part of?

series