input question: Generate a question about the topic "North American Free Trade Agreement" whose answer would be: The North American Free Trade Agreement (NAFTA) is an agreement signed by Canada , Mexico , and the United States , creating a trilateral trade bloc in North America ..???
output answer: What is the purpose of North American Free Trade Agreement?
Generate a question about the topic "Osaka" whose answer would be: Located at the mouth of the Yodo River on Osaka Bay , Osaka is Japan's third largest city by population after Tokyo (special wards) and Yokohama ..
----
Answer: where is osaka japan?
Q: Generate a question about the topic "Mathematical constant" whose answer would be: A mathematical constant is a special number , usually a real number , that is "significantly interesting in some way"..
A: what is a constant in math??
Question: Generate a question about the topic "Wendy Williams" whose answer would be: Wendy Williams Hunter (born Wendy Joan Williams; July 18, 1964) is an American media personality , actress and author..
Answer: what nationality is wendy williams?
[Q]: Generate a question about the topic "At sign" whose answer would be: The at sign @ is also commonly called the at symbol, ampersat, apetail or commercial at in English—and less commonly a wide range of other terms..
****
[A]: what is the @ sign called??
Problem: Given the question: Generate a question about the topic "Defragmentation" whose answer would be: In the maintenance of file systems , defragmentation is a process that reduces the amount of fragmentation ..
++++++++++++++++++++++++++++++++
The answer is:

What is the disk defragmenter tool?