Determine the topic of the question. Question: "where did the persian war take place?" Topic:
Ans: Greco-Persian Wars

Determine the topic of the question. Question: "how is rfid tag powered?" Topic:
Ans: Radio-frequency identification

Determine the topic of the question. Question: "what makes a dwarf planet?" Topic:
Ans: Dwarf planet

Determine the topic of the question. Question: "who is is the singer westlife?" Topic:
Ans: Westlife