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').

Q: Most children improve in three to ____ days.\Question: Choose the right answer from options given a) seven b) six c) four d) ten

A: a
****
Q: Human feet bear average five to ____ hundreds tons of weight everyday.\Question: Choose the right answer from options given a) six b) eight c) five d) nine

A: a
****
Q: Cancer can take ____ or more years to develop.\Question: Choose the right answer from options given a) no b) four c) seven d) six

A:
d
****