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]: Motor neurons are divided into ____ groups.\Question: Choose the right answer from options given a) two b) six c) seven d) eight
[EX A]: a

[EX Q]: Stringers consist of ____ narrow pieces of wood glued together.\Question: Choose the right answer from options given a) ten b) three c) five d) seven
[EX A]: b

[EX Q]: Otters can have ____ litters of pups a year.\Question: Choose the right answer from options given a) two b) six c) three d) five
[EX A]:
a