Generate a question which can yield the answer mentioned in the input. Generated question must be answered by the answer provided in input, without using any extra knowledge.

Context : Montasio is a mountain cheese made from cow's milk produced in northeastern Italy in the regions of Friuli-Venezia Giulia and Veneto. 
Answer : cow's milk
What material was used for Montasio?

Context : The Doorbell Rang is a Nero Wolfe detective novel by Rex Stout, first published by the Viking Press in 1965. 
Answer : Nero Wolfe
What series is The Doorbell Rang in?

Context : Filippo Volandri (born 5 September 1981; Italian pronunciation: (fiˈlippo voˈlandri)) is an Italian professional male tennis player. 
Answer : male

What sex is Filippo Volandri?