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.

[Q]: Context : Mainova AG was formed in 1998 through the merger of Stadtwerke Frankfurt am Main GmbH and Maingas AG. 
Answer : Stadtwerke Frankfurt
[A]: What is Mainova's parent company?


[Q]: Context : Høje Taastrup station is a railway station in Høje-Taastrup municipality, Denmark, opened on 31 May 1986. 
Answer : 1986
[A]: When was Høje Taastrup station founded?


[Q]: Context : The Revenge of Tarzan (1920) is a silent adventure film, originally advertised as The Return of Tarzan, and the third Tarzan film produced. 
Answer : The Return of Tarzan
[A]:
The The Revenge of Tarzan is based upon what?