Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

[EX Q]: Context: FreeBSD is a free Unix-like operating system descended from Research Unix via the Berkeley Software Distribution (BSD). 
 Question: The FreeBSD is based upon what?
[EX A]: berkeley software distribution

[EX Q]: Context: Villa Wartholz was designed by Heinrich von Ferstel in the historicist style in the years 1870 to 1872 for Archduke Karl Ludwig of Austria. 
 Question: What is the name of the Villa Wartholz architect?
[EX A]: heinrich von ferstel

[EX Q]: Context: The 2015 Russian Grand Prix (formally known as the 2015 Formula 1 Russian Grand Prix; Russian: 2015 -1 - ) was a Formula One motor race that took place on 11 October 2015. 
 Question: What date is associated with 2015 Russian Grand Prix?
[EX A]:
11 october 2015