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.

Ex Input:
Context : Christian de Boissieu received a Ph. D in economics in 1973 at the University of Paris-I Panthéon-Sorbonne. 
Question : What is the name university that educated Christian de Boissieu?

Ex Output:
educated at


Ex Input:
Context : Timelike Infinity is a 1992 science fiction book by Stephen Baxter. 
Question : What series is Timelike Infinity a part of?

Ex Output:
series


Ex Input:
Context : South African Airways Flight 228 was a scheduled flight of the Boeing 707-300C Pretoria, registration ZS-EUW, on 20 April 1968 from Johannesburg to Heathrow via Windhoek, Luanda, Las Palmas and Frankfurt. 
Question : What is the full date that South African Airways Flight 228 crashed on?

Ex Output:

point in time