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: Mothers typically have from one to ____ cubs, which are born blind and toothless.\Question: Choose the right answer from options given a) six b) zero c) four d) seven

A: a
****
Q: Cows can be up to ____ times more active than normal while in heat.\Question: Choose the right answer from options given a) eight b) nine c) two d) six

A: a
****
Q: Single bonds are one line, Double bonds are ____ lines.\Question: Choose the right answer from options given a) three b) nine c) two d) eight

A:
c
****