Generate a correct and concise answer for the question based on the words in the context.

[EX Q]: Context : Valentina Ivashova was married to Soviet film director Nikolai Ekk. 
Question : What is Valentina Ivashova's spouse's name?
[EX A]: Nikolai Ekk

[EX Q]: Context : Sunil Shroff is a urologist and transplant surgeon from India. 
Question : What was Sunil Shroff's occupation?
[EX A]: urologist

[EX Q]: Context : The Caledonian Railway 670 Class was a class of 0-4-2 steam locomotives designed by George Brittain for the Caledonian Railway (CR) and introduced in 1878. 
Question : Which was the official year for the approval of Caledonian Railway 670 Class?
[EX A]:
1878