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 olive trees live to be ____ thousand years old.\Question: Choose the right answer from options given a) ten b) zero c) two d) seven
[EX A]: c

[EX Q]: Trains kill ____ people every year.\Question: Choose the right answer from options given a) zero b) three c) no d) four
[EX A]: d

[EX 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
[EX A]:
a