D is the correct answer.
A -> If you're referring to someone else's purple bow, you would say "yours." Not "your's."
B -> "Theirs" is gramatically incorrect. You would just say "their."
C -> "It's" is used in the wrong way. You would just say "its rightful owner." "It's" refers to "it is" & if you plug that into the sentence, it makes no sense.
Hope this helped! :)
