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').

Cougars have ____ toes with three distinct lobes present at the base of the pad.\Question: Choose the right answer from options given a) no b) four c) eight d) zero
b

Nodes are points in space that have ____ probability for locating an electron there.\Question: Choose the right answer from options given a) no b) six c) zero d) three
c

Every animal is run by ____ primary instinctual drives.\Question: Choose the right answer from options given a) one b) three c) eight d) two

b