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: Islamic practice is based on what are called the ____ pillars of faith.\Question: Choose the right answer from options given a) eight b) one c) five d) four
Example Output: c

Example Input: Some taxonomists classify only ____ species though.\Question: Choose the right answer from options given a) one b) six c) two d) three
Example Output: c

Example Input: Hominids are primates with ____ tails , robust bodies and well-developed forearms .\Question: Choose the right answer from options given a) nine b) eight c) ten d) no
Example Output:
d