In which one of the following sentences is the apostrophe used correctly?

a. the train began it's journey across country.
b. the cat licked it's paws while the dog watched.
c. it's up to you to decide what to do.
d. i put the letter back into it's file.

the answer is C. it says “It is up to you to decide what to do.”

C because if replaced with it is c is the one that makes sense

i would like to compare these two interpretations of the crucible : 1) eric christ's interretation and wade bradford's interpretation. the main differences between there interretaions is that in the first one you can notice direct link to joseph mccarthy whereas the second one represents how the town is filled with hysteria.the second interpretation shows that author believes that the story   about puritan town in salem is based on actual events while the first example shows the sencible reference to sort of bias.

the future of her and bobby