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: Many soils have ____ major layers or horizons, top soil, subsoil and parent material.\Question: Choose the right answer from options given a) one b) two c) seven d) three
Example Output: d

Example Input: Stringers consist of ____ narrow pieces of wood glued together.\Question: Choose the right answer from options given a) ten b) three c) five d) seven
Example Output: b

Example Input: Pinks reach maturity in ____ years.\Question: Choose the right answer from options given a) ten b) one c) eight d) two
Example Output:
d