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: Paleontologists specialize in ____ main areas.\Question: Choose the right answer from options given a) eight b) five c) no d) six

Answer: b


Question: Hybridization is the practice of ____ different species interbreeding.\Question: Choose the right answer from options given a) no b) one c) two d) three

Answer: c


Question: Moon rocks are typically ____ billion years old or older.\Question: Choose the right answer from options given a) five b) three c) eight d) one

Answer:
b