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]: Embrasures have ____ functions.\Question: Choose the right answer from options given a) three b) seven c) zero d) nine
[A]: a


[Q]: Most volcanoes erupt for ____ to four weeks and then rest.\Question: Choose the right answer from options given a) three b) four c) one d) eight
[A]: a


[Q]: Some physicians use a diagram of a hand and wrist, which is usually divided into ____ regions.\Question: Choose the right answer from options given a) six b) five c) two d) zero
[A]:
a