The prounoun "that" is used as a demonstrative pronoun in your sentence because it is used to demonstrate, or indicate something. In your sentence, that indicates which horse is your favorite.
I would be helpful to add a context. That way I'm able to properly answer.
Answer:
changed by an hour with every 15 of longitude
Answer:
It allows the speaker to set up the contrast to his or her own views.
Explanation:
I just took the test
