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').

Today there are ____ federal states, each based on cultural affiliations.\Question: Choose the right answer from options given a) one b) nine c) seven d) zero
b

Alleles segregate independently yielding ____ possible allelic combinations in gametes.\Question: Choose the right answer from options given a) ten b) one c) four d) nine
c

Most voles are less than ____ inches, and have a short, fur-covered tail.\Question: Choose the right answer from options given a) three b) six c) no d) ten

a