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: Most marine sediments are of ____ basic types.\Question: Choose the right answer from options given a) three b) ten c) two d) nine

A: c
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Q: Hybridization is the practice of ____ different species interbreeding.\Question: Choose the right answer from options given a) no b) one c) two d) three

A: c
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Q: Bats actually echolocate using ____ different systems, depending on the species of bat.\Question: Choose the right answer from options given a) one b) six c) two d) three

A:
d
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