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: Real airplanes have round engines and ____ wings.\Question: Choose the right answer from options given a) four b) six c) three d) two

Output: d


Input: Consider Input: Decapod crustaceans have ____ pairs of limbs.\Question: Choose the right answer from options given a) five b) four c) six d) seven

Output: a


Input: Consider Input: Frogs commonly have ____ legs and one foot on each leg.\Question: Choose the right answer from options given a) three b) no c) four d) five


Output: c