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').

Cats have ____ sets of vocal cords.\Question: Choose the right answer from options given a) zero b) nine c) two d) three
c

Sea stars have ____ arms, or rays, connected to a small round body.\Question: Choose the right answer from options given a) five b) six c) seven d) no
a

Mediators use ____ skills to help people communicate.\Question: Choose the right answer from options given a) one b) no c) zero d) two

d