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').
--------
Question: Cigarette smokers are ____ times more likely to die of lung cancer than nonsmokers.\Question: Choose the right answer from options given a) ten b) six c) four d) nine

Answer: a


Question: Elephants have four molars, which are replaced ____ times, for a total of six sets in a lifetime.\Question: Choose the right answer from options given a) five b) no c) three d) one

Answer: a


Question: Most intestinal worms take three to ____ weeks for maturation from their larval stages into adults.\Question: Choose the right answer from options given a) six b) three c) four d) ten

Answer:
c