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').

[EX Q]: Chipmunks produce one or ____ litters a year.\Question: Choose the right answer from options given a) three b) one c) ten d) two
[EX A]: d

[EX Q]: Avian kidneys have ____ kinds of nephrons.\Question: Choose the right answer from options given a) four b) eight c) no d) two
[EX A]: d

[EX Q]: Hazardous waste is categorized into ____ types.\Question: Choose the right answer from options given a) nine b) two c) ten d) eight
[EX A]:
b