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').

Ex Input:
Organisms have ____ forms of nucleic acid.\Question: Choose the right answer from options given a) four b) three c) two d) one

Ex Output:
c

Ex Input:
Some European countries require ____ years of education.\Question: Choose the right answer from options given a) no b) nine c) six d) three

Ex Output:
d

Ex Input:
Lizards require five to ____ feedings per week due to their high metabolic rates.\Question: Choose the right answer from options given a) seven b) six c) ten d) zero

Ex Output:
a