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: Selenium is ____ times more poisonous than arsenic.\Question: Choose the right answer from options given a) one b) five c) eight d) two

Answer: b


Question: Some programming languages have ____ or more standards.\Question: Choose the right answer from options given a) no b) seven c) two d) three

Answer: c


Question: Raman amplifiers are ____ key optical amplification techniques.\Question: Choose the right answer from options given a) two b) no c) zero d) five

Answer:
a