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]: Some taxonomists classify only ____ species though.\Question: Choose the right answer from options given a) one b) six c) two d) three
[EX A]: c

[EX Q]: Some people have ____ symptoms until the liver has been quite severely damaged.\Question: Choose the right answer from options given a) eight b) no c) nine d) ten
[EX A]: b

[EX Q]: Blood has ____ main constituents.\Question: Choose the right answer from options given a) three b) ten c) six d) two
[EX A]:
d