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: Tetrapods are animals that have ____ legs or leg-like appendages.\Question: Choose the right answer from options given a) four b) one c) ten d) six

Output: a


Input: Consider Input: Litters contain from one to ____ kittens, and tend to be much larger when prey is abundant.\Question: Choose the right answer from options given a) three b) four c) two d) seven

Output: b


Input: Consider Input: Proturans have small appendages ventral on the first ____ abdominal segments.\Question: Choose the right answer from options given a) three b) five c) eight d) two


Output: a