You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.

Q: Category: LADS NAMED VLAD 
Clue: In 1929, while working for RCA, this inventor & engineer demonstrated the first practical all-electronic TV

A: vladimir zworykin
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Q: Category: MR. BODY 
Clue: Fed by the hepatic portal veins, it weighs about a pound more in men than in women

A: liver
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Q: Category: GEMS & JEWELRY 
Clue: An English art critic said this gem "shows the most glorious colors to be seen in the world..."

A:
the opal
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