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]: Many scientists believe the neutrino has ____ mass at all.\Question: Choose the right answer from options given a) eight b) zero c) two d) no
[A]: d


[Q]: Mares normally give birth to their first foal when they are between three and ____ years of.\Question: Choose the right answer from options given a) ten b) no c) six d) four
[A]: c


[Q]: Antidepressants take from four to ____ weeks to have a strongly beneficial effect.\Question: Choose the right answer from options given a) six b) zero c) two d) eight
[A]:
a