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]: Decompression illness is a continuum from ____ symptoms or signs to severe multisystem involvement.\Question: Choose the right answer from options given a) nine b) three c) no d) one
[A]: c


[Q]: Anthrax usually is a fatal disease with ____ symptoms observed.\Question: Choose the right answer from options given a) no b) seven c) one d) six
[A]: a


[Q]: Photoelectric cells are of ____ kinds, vacuum and gas-filled.\Question: Choose the right answer from options given a) two b) zero c) three d) seven
[A]:
a