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').

[Q]: Double price is based on two golfers sharing ____ room.\Question: Choose the right answer from options given a) one b) zero c) six d) nine
[A]: a


[Q]: Most resistors have three coloured bands close together at one end and ____ single band at the other.\Question: Choose the right answer from options given a) two b) one c) ten d) five
[A]: b


[Q]: Hybrid systems are dynamical systems with ____ levels of description.\Question: Choose the right answer from options given a) nine b) three c) four d) two
[A]:
d