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').

Example Input: Baby elephants are usually dependent on mother s milk for at least ____ years.\Question: Choose the right answer from options given a) six b) three c) two d) seven
Example Output: b

Example Input: Japan is a highly urbanised country, with approximately ____ in every four people living in cities.\Question: Choose the right answer from options given a) ten b) no c) five d) three
Example Output: d

Example Input: 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
Example Output:
c