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').

Kabbalists group the simple letters into ____ triplets.\Question: Choose the right answer from options given a) four b) no c) ten d) three
a

Mothers usually give birth to one, two, or ____ babies at a time.\Question: Choose the right answer from options given a) three b) zero c) five d) ten
a

Fitnesses are important numbers in evolutionary theory and can be estimated by ____ main methods.\Question: Choose the right answer from options given a) five b) four c) three d) no

c