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: Many comets have ____ tails.\Question: Choose the right answer from options given a) two b) six c) three d) one

A: a
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Q: Ants have ____ noses.\Question: Choose the right answer from options given a) zero b) eight c) five d) three

A: c
****
Q: All plants are on their own roots, but there are ____ signs of root rots.\Question: Choose the right answer from options given a) no b) four c) one d) nine

A:
a
****