TASK DEFINITION: Generate a correct and concise answer for the question based on the words in the context.
PROBLEM: Context : By the start of World War II Heinz Hämel had been promoted to Oberscharführer (Technical Sergeant) and was a platoon commander. 
Question : Which war did Heinz Hämel serve in?

SOLUTION: World War II

PROBLEM: Context : OPML (Outline Processor Markup Language) is an XML format for outlines (defined as ``a tree, where each node contains a set of named attributes with string values''). 
Question : Which is the basis of OPML?

SOLUTION: XML

PROBLEM: Context : Crash Investigation Unit is an Australian factual television series on the Seven Network hosted by Damian Walshe-Howling. 
Question : What network is Crash Investigation Unit associated with?

SOLUTION:
Seven Network