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: Corms are undifferentiated, uniform, and contain ____ rings when cut apart.\Question: Choose the right answer from options given a) no b) three c) one d) zero

A: a
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Q: Basting is the stitching used to hold the ____ layers of fabric together while quilting.\Question: Choose the right answer from options given a) four b) six c) three d) ten

A: c
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Q: Some European countries require ____ years of education.\Question: Choose the right answer from options given a) no b) nine c) six d) three

A:
d
****