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.

[EX Q]: Context : Trace of Stones (German: Spur der Steine) is a 1966 East German film by Frank Beyer. 
Answer : Spur der Steine
[EX A]: The Trace of Stones is based upon what?

[EX Q]: Context : ISO 3166-2:PN is the entry for the Pitcairn Islands in ISO 3166-2, part of the ISO 3166 standard published by the International Organization for Standardization (ISO), which defines codes for the names of the principal subdivisions (e.g., provinces or states) of all countries coded in ISO 3166-1. 
Answer : International Organization for Standardization
[EX A]: Who set the standards for ISO 3166-2:PN?

[EX Q]: Context : When the Federal German Navy was established in 1956, Dochet and Flint were acquired and classified as Type 139 patrol trawlers. 
Answer : 1956
[EX A]:
In which year was the service entry date for Type 139 patrol trawler?