You will be given a context, a subject and a relation. Your task is to generate a question based on the subject and relation. The generated question should include the given subject. Try to use a minimum number of words that are not present in either context, subject or relation while generating question.

Context : The GER Class Y65 was a class of twelve 2-4-2T steam locomotives designed by S. D. Holden and built by the company's Stratford Works in 1909--1910. 
Subject : GER Class Y65 
Relation : service entry
What year was GER Class Y65 introduced?

Context : Desert Combat (DC) is a mod for the first-person shooter (FPS) computer game Battlefield 1942, created by Trauma Studios. 
Subject : Desert Combat 
Relation : based on
Which is the basis of Desert Combat?

Context : Allman was married to pop star Cher for the rest of the decade, while he continued his solo career with the Gregg Allman Band. 
Subject : Gregg Allman 
Relation : spouse

What is Gregg Allman's spouse's name?