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').

Example Input: Tilt consists of ____ small surface vents.\Question: Choose the right answer from options given a) zero b) three c) seven d) no
Example Output: b

Example Input: Dicots have ____ seeds leaves, whereas monocots have only one.\Question: Choose the right answer from options given a) four b) one c) seven d) two
Example Output: d

Example Input: Fluorescent lights are ____ to four times more energy-efficient.\Question: Choose the right answer from options given a) ten b) three c) zero d) four
Example Output:
b