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').

TriMetal Irons Discover the benefits of ____ different metals.\Question: Choose the right answer from options given a) five b) seven c) no d) three
d

Mothers typically have from one to ____ cubs, which are born blind and toothless.\Question: Choose the right answer from options given a) six b) zero c) four d) seven
a

Autotrophic organisms can use all ____ forms.\Question: Choose the right answer from options given a) three b) six c) eight d) four

a