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]: Many aneurysms have ____ symptoms until they burst.\Question: Choose the right answer from options given a) no b) five c) six d) seven
[EX A]: a

[EX Q]: Humans learn through the ____ senses.\Question: Choose the right answer from options given a) eight b) one c) five d) ten
[EX A]: c

[EX Q]: Lactase is composed of ____ sugars.\Question: Choose the right answer from options given a) ten b) four c) six d) two
[EX A]:
d