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 bacteria have one or ____ circular chromosomes.\Question: Choose the right answer from options given a) ten b) eight c) six d) two
Example Output: d

Example Input: Death occurs during the first ____ days of illness without intensive care.\Question: Choose the right answer from options given a) seven b) eight c) five d) nine
Example Output: a

Example Input: Hexapods comprise insects and three small orders of insect-like animals with ____ thoracic legs.\Question: Choose the right answer from options given a) four b) zero c) six d) three
Example Output:
c