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: Pneumatic motor is a six-point unit with ____ pneumatics facing up and three facing down.\Question: Choose the right answer from options given a) five b) no c) three d) nine

Answer: c


Question: Psychiatrists say that one in ____ people are mentally ill.\Question: Choose the right answer from options given a) one b) two c) four d) nine

Answer: c


Question: Foods are of ____ types, acid or alkaline.\Question: Choose the right answer from options given a) zero b) one c) ten d) two

Answer:
d