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:
Vaporization can occur in temperatures as low as ____ degrees.\Question: Choose the right answer from options given a) one b) zero c) eight d) two

Ex Output:
b


Ex Input:
Stroke is the number ____ cause of death in the United States.\Question: Choose the right answer from options given a) ten b) nine c) one d) three

Ex Output:
d


Ex Input:
Metallic fabrics have ____ problems being carefully hand-washed in cool water.\Question: Choose the right answer from options given a) five b) no c) six d) three

Ex Output:

b