Which sentence uses possessive personal pronouns correctly?

a.
theirs favorite show will come on at eight o'clock.

b.
that box with the large purple bow is your's.

c.
are those jeans hers or his?

d.
the wallet has been returned to it's rightful owner.

C. Are those jeans hers or his.

D, is using the contraction "it is" not the possessive, "its". Theirs would not be correct either because you are talking about one group and one thing, so A is incorrect. B, is not right because "your's" would be "yours". So C is correct because hers and his makes sense.