Problem: Given the question: What is the question to: "The town is located about south of Paris and east of Orleans in the Gatinais ."? The topic is Montargis.
++++++++++++++++++++++++++++++++
The answer is:
"What region of France is Montargis in??"

Problem: Given the question: What is the question to: "Add-ons for Firefox (addons.mozilla.org), the official Mozilla Foundation web site which serves as a repository of add-ons for Mozilla-based applications"? The topic is Add-on.
++++++++++++++++++++++++++++++++
The answer is:
"what are add ons?"

Problem: Given the question: What is the question to: "Most of the hydrogen on Earth is in molecules such as water and organic compounds because hydrogen readily forms covalent compounds with most non-metallic elements."? The topic is Hydrogen.
++++++++++++++++++++++++++++++++
The answer is:
"What is hydrogen in?"