input question: Determine the topic of the question. Question: "where did columbus really land in 1492??" Topic:???
output answer: Christopher Columbus

Determine the topic of the question. Question: "who is the CEO OF FACEBOOK?" Topic:
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Answer: Mark Zuckerberg

Q: Determine the topic of the question. Question: "what is tmz stand for?" Topic:
A: TMZ (website)

Question: Determine the topic of the question. Question: "how south african leaders are elected?" Topic:
Answer: President of South Africa

[Q]: Determine the topic of the question. Question: "What is Ischemia or infarction??" Topic:
****
[A]: Ischemia

Problem: Given the question: Determine the topic of the question. Question: "what is middle class in the us?" Topic:
++++++++++++++++++++++++++++++++
The answer is:
American middle class