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: Japan is a highly urbanised country, with approximately three in every ____ people living in cities.\Question: Choose the right answer from options given a) seven b) two c) four d) eight

Answer: c


Question: Alleles segregate independently yielding ____ possible allelic combinations in gametes.\Question: Choose the right answer from options given a) ten b) one c) four d) nine

Answer: c


Question: Vacuum tubes have essentially ____ basic types of emitters.\Question: Choose the right answer from options given a) three b) seven c) zero d) six

Answer:
a