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').

Illiteracy is ____ percent higher among women than men.\Question: Choose the right answer from options given a) seven b) six c) zero d) five
a

Manatees swim two to ____ miles per hour.\Question: Choose the right answer from options given a) no b) six c) five d) zero
b

Calves stay close to their mothers for ____ years.\Question: Choose the right answer from options given a) two b) no c) eight d) five

a