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').

Female bilbies have a backward-opening pouch with ____ nipples.\Question: Choose the right answer from options given a) no b) two c) five d) eight
d

Pups remain in the den for about ____ weeks, and are cared for by the entire pack.\Question: Choose the right answer from options given a) ten b) three c) six d) no
c

Most spider beetles have two or ____ generations per year.\Question: Choose the right answer from options given a) three b) one c) seven d) nine

a