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').

Altimetric satellites are usually limited life missions lasting approximately three to ____ years.\Question: Choose the right answer from options given a) five b) ten c) four d) eight
b

Baboons can travel up to ____ miles a day.\Question: Choose the right answer from options given a) seven b) three c) two d) six
d

Comets are visible for ____ reasons.\Question: Choose the right answer from options given a) two b) eight c) six d) nine

a