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: Sugar beet is strongly self-sterile setting few or ____ seeds under strict isolation.\Question: Choose the right answer from options given a) three b) no c) five d) nine
Example Output: b

Example Input: Elephants give birth to ____ calf every four to nine years on average.\Question: Choose the right answer from options given a) ten b) one c) eight d) six
Example Output: b

Example Input: Body has more than ____ cell layers, tissues and organs.\Question: Choose the right answer from options given a) two b) seven c) ten d) four
Example Output:
a