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').

Q: Amelia Island is the only territory in American history to serve under ____ flags.\Question: Choose the right answer from options given a) eight b) no c) six d) five

A: a
****
Q: Black widows mature in ____ to four months.\Question: Choose the right answer from options given a) two b) seven c) eight d) zero

A: a
****
Q: Protons contain two up quarks and ____ down quark.\Question: Choose the right answer from options given a) eight b) one c) three d) seven

A:
b
****