Given a sentence with a missing word, pick the answer option that best fills out the missing word in the sentence. Indicate each answer with its index ('a', 'b', 'c', 'd').

Q: Reverse osmosis uses ____ to ten gallons of water to produce one gallon of drinking water.\Question: Choose the right answer from options given a) two b) zero c) five d) three

A: d
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Q: All butterflies go through ____ life stages .\Question: Choose the right answer from options given a) one b) four c) zero d) five

A: b
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Q: Drip irrigation sends water straight to a plant's roots with virtually ____ loss to evaporation.\Question: Choose the right answer from options given a) no b) six c) one d) four

A:
a
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