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: Most resistors have three coloured bands close together at one end and ____ single band at the other.\Question: Choose the right answer from options given a) two b) one c) ten d) five
Example Output: b

Example Input: Marriage is the legal union of ____ people.\Question: Choose the right answer from options given a) one b) no c) five d) two
Example Output: d

Example Input: Brazil is among the top ____ producers of beef.\Question: Choose the right answer from options given a) two b) eight c) zero d) ten
Example Output:
d