Question

Which sentence uses possessive pronouns correctly? A. Is the puppy in the yard your's? B. Here comes her friend Jacob, walking down the street. C. We watched the horse eating it's oats. D. Her's is the straw hat with the wide brim.

Answer 1

The sentence that correctly uses pronouns is C. We watched the horse eating it's oats. 

Remember that possessive noun includes our, mines, theirs, hers. ETC..

Answer 2

B is the only correct answer.
A should be "yours"
C should be "its"
D should be "hers"