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').
--------
Question: Ammonia is among the ____ most abundantly produced chemicals in the world.\Question: Choose the right answer from options given a) five b) zero c) no d) eight

Answer: a


Question: Ankle joint has ____ degrees of freedom.\Question: Choose the right answer from options given a) seven b) eight c) four d) three

Answer: d


Question: Caterpillars shed their skins four or ____ times as they grow, in a process called molting.\Question: Choose the right answer from options given a) five b) seven c) zero d) no

Answer:
a