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: Elephants give birth to one calf every ____ to nine years on average.\Question: Choose the right answer from options given a) no b) four c) three d) seven
Example Output: b

Example Input: Conflict diamonds account for less than ____ per cent of world trade in rough diamonds.\Question: Choose the right answer from options given a) two b) four c) one d) ten
Example Output: b

Example Input: Sapsuckers are a group of ____ species known for literally drinking the sap of trees.\Question: Choose the right answer from options given a) ten b) nine c) four d) eight
Example Output:
c