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: Sexual reproduction involves ____ parents, one male and one female.\Question: Choose the right answer from options given a) zero b) two c) nine d) four

Output: b


Input: Consider Input: Echinoderms usually have ____ appendages, but there are some exceptions.\Question: Choose the right answer from options given a) ten b) five c) seven d) three

Output: b


Input: Consider Input: Diabetes has ____ forms, insulin dependent and non insulin dependent.\Question: Choose the right answer from options given a) ten b) six c) seven d) two


Output: d