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').

[EX 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
[EX A]: a

[EX Q]: Chemical interactions are essentially electron interactions of ____ atoms.\Question: Choose the right answer from options given a) six b) no c) ten d) two
[EX A]: d

[EX Q]: Advanced countries use steel about three to ____ times more than cement compared to India.\Question: Choose the right answer from options given a) eight b) five c) three d) two
[EX A]:
b