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').

Ex Input:
Chimeras are ____ headed creatures that shoot fire from all three heads, damaging a wide area.\Question: Choose the right answer from options given a) three b) one c) eight d) six

Ex Output:
a


Ex 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

Ex Output:
d


Ex Input:
Progeria occurs in ____ forms.\Question: Choose the right answer from options given a) five b) one c) two d) six

Ex Output:

c