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]: Reservoirs cover an area of the planet ____ times the size of Britain.\Question: Choose the right answer from options given a) two b) eight c) three d) six
[EX A]: d

[EX Q]: Indian reservations are part of five of the nation's ____ poorest counties.\Question: Choose the right answer from options given a) seven b) nine c) ten d) two
[EX A]: c

[EX Q]: Gene symbols consist of ____ lowercase letters.\Question: Choose the right answer from options given a) two b) nine c) three d) no
[EX A]:
c