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.

Input: Consider Input: Context : Gelnhausen railway (Hungen--Gießen) was opened on 29 December 1869 and Hungen station went into operation. 
Answer : 29 December 1869

Output: When was Hungen station opened?


Input: Consider Input: Context : Pedro de Oña (1570--1643) is considered the first known poet born in Chile, and is best remembered for his verse epic poem Primera parte de Arauco domado (``First Part of the Araucan Conquest''). 
Answer : 1643

Output: What was the death date of Pedro de Oña?


Input: Consider Input: Context : YugoRosGaz a.d. is a Gazprom subsidiary in Serbia. 
Answer : Gazprom


Output: What company is YugoRosGaz part of?