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').

[EX Q]: Songbirds have ____ sets of vocal chords.\Question: Choose the right answer from options given a) six b) two c) eight d) ten
[EX A]: b

[EX Q]: Ankle joint has ____ degrees of freedom.\Question: Choose the right answer from options given a) seven b) eight c) four d) three
[EX A]: d

[EX Q]: Perennials survive ____ or more seasons.\Question: Choose the right answer from options given a) six b) ten c) three d) no
[EX A]:
c