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 Q]: Chemical interactions are essentially electron interactions of ____ atoms.\Question: Choose the right answer from options given a) six b) no c) ten d) two
[EX A]: d

[EX Q]: Fever usually lasts for an average of ____ days in adults.\Question: Choose the right answer from options given a) zero b) three c) nine d) two
[EX A]: b

[EX Q]: Iambic tetrameter has ____ such feet, for a total of eight syllables.\Question: Choose the right answer from options given a) nine b) four c) eight d) six
[EX A]:
b