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').

Input: Consider Input: Butterflies have ____ stages in their life cycle.\Question: Choose the right answer from options given a) two b) four c) no d) eight

Output: b


Input: Consider Input: Fluorescent lamps are roughly ____ times more intense than ordinary lightbulbs.\Question: Choose the right answer from options given a) six b) one c) three d) eight

Output: c


Input: Consider Input: 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


Output: d