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').

Corms are undifferentiated, uniform, and contain ____ rings when cut apart.\Question: Choose the right answer from options given a) no b) three c) one d) zero
a

Lions have ____ distinct vocalizations including roars, grunts and growls.\Question: Choose the right answer from options given a) eight b) six c) four d) nine
d

Fire point is the lowest temperature at which burning is sustained for ____ seconds.\Question: Choose the right answer from options given a) nine b) one c) five d) eight

c