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: Scorpions can live for ____ to seven years.\Question: Choose the right answer from options given a) one b) six c) five d) three

A: d
****
Q: Reverse osmosis uses three to ____ gallons of water to produce one gallon of drinking water.\Question: Choose the right answer from options given a) six b) eight c) five d) ten

A: d
****
Q: Cats have ____ toes on their front paws, but only four touch the ground when walking.\Question: Choose the right answer from options given a) six b) nine c) five d) zero

A:
c
****