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: Ants have six legs, and each leg has ____ joints.\Question: Choose the right answer from options given a) nine b) zero c) two d) three
Example Output: d

Example Input: Casinos have no windows and they have ____ clocks.\Question: Choose the right answer from options given a) six b) four c) eight d) no
Example Output: d

Example Input: Most dens are oval shape, six to ____ feet long and about six feet in height and width.\Question: Choose the right answer from options given a) no b) seven c) one d) nine
Example Output:
d